(FAR) Getting the Contract Research Paper Example | Topics and Well Written Essays - 750 words

(FAR) Getting the Contract - Research Paper Example 87). The pre-negotiation process may be very important to the company’s contractor because the efforts invested before going into the negotiations may be very instrumental in guaranteeing that the government will offer the contracts to the company. Some of the pre-negotiation activities that the company, in general, and the contractor will need to take include, collecting the company’s internal data that may be relevant to the negotiation; analyzing it, and using it as the lens, through which the future plans of the company can be formulated (Tomlin, 1989). After developing a clear picture of the future plans of the company, the company as a whole as well as the contractor will need to define the outcomes expected from the negotiation process, and also explore the goals of the government. The goals of the government, similar those of the company will be very instrumental in determining whether it will choose the company; which will depend on the company’s understanding of the goals and its potential to meet the government’s goals. The company can only be selected when the government conceives that it understands the goals to be realized through the contracts (Guth, 2008). By ensuring that the activities/steps mentioned before have been taken, the company should have gone through the three major stages of the pre-negotiation process. The three pre-negotiation stages that apply to the contractual negotiations of the company with the government include that the actions will enable the company to establish a relationship with the government (Tomlin, 1989). The second stage that will have been met is that the company will have gathered all the necessary information about the industry and the government, which will guarantee that it will offer its attention to valid data and information only. The third stage that will have been completed will be that of setting the

Importance of Information System Auditing

Importance of Information System Auditing Evaluation of Effectiveness of Auditing of Information System within Corporate Governance Structure in the UK business organizations. Abstract This dissertation will research and review the conceptual framework of effectiveness of auditing (internal audit) of information system within the Corporate Governance structure, where information technology is deemed a key to system success or failure. The paper will then aim to focus on case study approach on two industry sectors in UK to explore a within correlation within effectiveness of Audit function and Corporate Governance structure through a lens of clear transparent information flow and system by means of technology innovation through accountability. Introduction The overall focus of this dissertation is around the critically analyzing and evaluation of auditing of information system in corporate governance structure with strategic significance of information and technology. Auditing of information system is sometimes referred as IT auditing that in modern language that states flow of information processes throughout the organization that is integral part of strong and affective corporate governance. Information integrity and disclosure is the key to successful governance. Corporate Governance has accomplished developing acknowledgment in recent years in light of financial reporting scandals, for example, Enron, WorldCom and Parmalat, which lessened trust in the freedom and unwavering quality of the auditing profession involved, as well as the accounting profession and financial markets all in all (Ibrahim El-Sayed Ebaid, 2011). Inside this structure of present day business world, the part of an inner control framework is synergist since it is viewed as a source from which center capacities are given or drawn and are in this way changed into upper hands. Be that as it may, the pivotal part of internal auditing for the business accomplishment, there is no such a review examining the collaboration between internal auditing and corporate governance (Karagiorgos et al., 2010). For the above reasons the motivation behind this research is to focus on the evaluation of effectiveness of Auditing of Information System within Corporate Governance Structure in th e UK business organizations. Auditing is one of the fundamental components for the effective working of the business and makes a difference an association to confront the outer world with exact data on its business and issues identified related to accountability. Initially auditing function was essentially concerned with just the money and finance related issues inside the business that is accounts for the business. Evidently, the income created by the organization and the costs related are the major contributing variables for decision making on the tax and shareholder benefits. Close by, the development of data innovation (IT) and the expansion in people in general awareness has assist heightened the requirement for directing a proficient auditing procedure to give accountability to their business exercises. It is also vital that the corporate governance of an organization is fundamental for the advantage of the partners as well as for the financial dependability in the business showcase and in addition the whole country. This research is aimed to display a critical research and evaluation of effectiveness of Auditing of Information System within Corporate Governance Structure in the UK business organizations. The research will toss light on the different perspectives identify with accomplishing adequacy in through evaluating information system as one of the component of corporate administration and basically investigations of the innovation and technology on information transparency. Aim and Objectives The focal point of this thesis will be to analyze the productivity of auditing of information system framework in the corporate administration among the UK business associations. This will be accomplished by the research on the following aim and objectives. To appraise the phenomenon of corporate governance and its effectiveness for an organization both inside and outside to the business. Critically analyse the role of information and development of information system frameworks within the scope of corporate governance. Research Definition The research will be refined and focused utilizing using secondary information resources only. This is mainly due to the fact that a general public opinion on the auditing of information system may be inappropriate and deficient as the business organizations may not disclose their corporates sensitive information apart from that is published in the annual submissions/report due to data protection and privacy (Leung, P.et al 2004).Thus the investigation through case study will be completely subjective in nature (i.e.) the exploration is based upon the journals and published white papers as opposed to utilizing primary information for measuring the analysis. The contextual critical examination will be led upon the vital energy and banking domains of the UK economy. While a basic investigation on HSBC bank Plc will be displayed under the banking area, National Grid Transco, Plc is the organization in question for the Energy segment of the UK. The contextual investigation on these organizations will give critical insight on the utilization information technology and the organizations endeavor to fulfill viability of effectiveness of auditing of information system related outcomes for corporate governance. Corporate governance context There had been much written and researched about corporate governance, IT audit, and Information system in literatures recently, but most research has been done considering one or two variables from different angles, such as Corporate Governance and Auditing, IT audit and Corporate Governance, Information System and Corporate Governance etc. Less been written from information perspective to explore Information System Audit and Corporate Governance viability specifically by use of technology in modern era of corporate world, that is the fundamental aim of this research. Following literature research explain and explore more about the individual concepts that prove essential ingredients to successful stewardship of the business. According toToffel, M.W. (2006), states that investors expression of need for information relevant to companys economical information is not just raw accounting data but interpretation lying within. He further states that asymmetric information and potentially adverse disclosure prompts a question mark to capabilities of corporate governance structure of companies.Baek et al. (2008) argues further that directors consider that they have disclosed full information that is required, yet most experts and financial specialists assert that they ought to try to do as such. Another aspect of delivery of information through the use of information system is e-commerce that is very popular and proved to be effective communication channel without side world, i.e. stakeholders. Yabing et al., 2010 concluded in his study that there are considerable number of organizations which dont utilize their websites to convey significant financial data to the external stakeholders users. A current review that has an example with 30 traded organizations disclosed that a great deal of organizations utilize their website in inappropriate way, particularly to communicate information considering corporate governance that pose a question to the stewardship of organization as a whole. To overcome this weakness and to mitigate potential risk to corporate governance auditing plays vital role by assessing overall information system of the organization. A vital clarification between governance and administration is made by Bird, F. (2001), states that while managers and officials control, create, monitor and execute business objectives on an everyday basis, directors and other board structures manage overall business strategy, culture and course. He further states that Executives manages organizations by morality of the authority commissioned to them by owners of the organization, hence making a strong contrast between the assorted components of corporate governance and management. Auditing Information System In modern IT era, the audit process quality within the organization have become an integral and fundamental part of corporate governance quality and transparency. As respects to this, the nature of information systems auditing has likewise accepted a parallel to that. The inherent feature of information systems auditing, and the abilities fundamental to do such reviews, ideally require all around substantial norms standards that execute particularly to information systems examination scrutiny. The amalgamation of Information Technology audit, arranging and methodology with corporate governance and the key utilization of data frameworks (IS) have been of topical subject to administration management experts and IT scholars for quite a while. The move of accentuation can be connected to changes in availability and cost execution proportions in innovation/technology. It can likewise be identified with subsequent changes in potential applications. The converging of hardware and interchanges innovations, and the more far reaching utilization of databases, systems, and coordinated frameworks requiring long-term audit and planning viewpoints, addit ionally fortified for powerful arrangement from corporate governance perspective in UK. IT Governance Kingsford, R., Dunn, L. furthermore, Cooper, J. (2003) states that Information Technology governance is referred to as a sub-set of corporate governance. It appears to be logical then that the meaning of corporate governance will give a helpful start off to an investigation of the definition and proper utilization of the term IT governance. One domain is the relatively recent focal point on corporate governance and the other is strategic information systems within the organization. Web, P. Pollard, C., Ridley, G. (2006),  Ãƒâ€šÃ‚   Attempting to Define IT Governance:   Wisdom or Folly? Strong governance has for some time been viewed as urgent for improving the long-term value of stakeholders in the organizational domain. In the new innovation driven information age, strengthen corporate governance is considered exceptional best practice and a key segment of market train. Recent demand from stakeholders, shareholders and others owners of business, for more prominent responsibility from corporate board and audit committees that will probably upgrade the nature of corporate stewardship and in the end prompt to more productive capital markets. However, Sarbanes Oxley report in US and the Cadbury Code in the United Kingdom that requires that audit committees adhere to certain professional guidelines rules (e.g., internal controls risk reporting requirements and disclosures), there are few generally acknowledged standards for good governance within the organization. Role of Information in Information System Audit Corporate Governance Ward, J. Peppard, J. (2002) argued that the information systems in a business enterprise not just incorporates the innovation and technology related items additionally those segments of the business that infect process and create yield from the information like the costs, income and purchases. Moreover, they emphasized that the vital utilization of information to encourage effective decision making by the senior administration of the organization, that certainly build the need to distinguish critical information and in addition keep up transparency of the information to furnish independence and accuracy with quality. Information system has seen vital development in each circle of business with the expansion in the competition and innovation technology (IIA, 2004) Christopher Barnatt (2000) contends that the corporate governance in a business organization despite the fact that grasps the reviewing of the fund and income building up a responsibility, predominantly relies on the information that is underlying the income streams or the cost brought about since the financial related measurement by the organization is construct upon the real information with respect to their everyday business. This further makes it clear that information is not just assumes a critical part in dealing with the review auditing information but also a key part in approving the crucial information that is really used to represent the income inside the organization. The above proclamation obviously clarifies that the data innovation (technology) in stepping stone for the business processes and income apart from just the element of client relationship etc. John Ward (2000) argued that the information system in a business domain with reference to corporate governance of the organization gives the underlying contributing milestone to the accountability of income transparency of the overall business. Furthermore, he poses the fact that the likelihood to give false information to cover any major issues inside the business will at the end may influence the corporate governance of the business. It is evident from the argument above that the innovation technology underlying information processing itself required to be formulated and validated in order to approve privacy and to counteract unapproved access to the data. References: Bird, F. (2001), Good governance: A Philosophical discussion of the responsibilities and practices of organizational governors, Canadian Journal of Administrative Studies, No. December,   298-312 Baek, Y.H., Kim, D., Kim, J.W. (2008) Management Earnings Forecasts and Adverse Selection Cost: Good vs Bad News Forecast, International Journal of Accounting and Information Management, Vol. 16, Issue 1, pp. 62-73. Christopher Barnatt, (2000), Management Strategy and Information Technology, Text and Readings, Thomson Business Press Ibrahim El-Sayed Ebaid, (2011) Corporate governance practices and auditors client acceptance decision: empirical evidence from Egypt, Corporate governance, 11(2), pp. 171-183. Institute of Internal Auditors UK, (2004), IT Audit, UK John Ward and Joe Peppard, (2002), Strategic Planning and information Systems, 3rd edition, John Wiley and Sons Karagiorgos, T., Drogalas, G., Tampakoudis, I. and Gotzamanis, Ά¢. (2010) Internal Auditing as an effective tool For Corporate Governance, Journal of Business Mgt, 2(1), International Science Press. Kingsford, R., Dunn, L. and Cooper, J. (2003), Information Systems, Information Technology Governance and Organizational Culture, in 14th Australasian Conference on Information Systems, Perth, Australia. Leung, P., Cooper, B.J. and Robertson, P. (2004) The role of Internal Audit in Corporate Governance and Management, RMIT Publishing, Melbourne. Toffel, M.W. (2006) Resolving Information Asymmetries in Markets: The Role of Certified Management Programs, Working paper, Division of Research, Harvard Business School, Vol. 7. Web, P., Ridley, G., Pollard, C. (2006), Attempting to Define Information Technology Governance:   Wisdom or Folly? 39th Hawaii International Conference on System Sciences 2006, Australia Yabing J, Viju R. and Wullianallur R. (2009), Web-Based Corporate Governance Information Disclosure: An Empirical Investigation Volume 22, Issue 2. 19 pages

Animal Farm Relating To Russia :: Animal Farm Essays

Greed for Power, and Cruelty: Making Followers In Animal Farm, George Orwell demonstrates the danger of unquestioning acceptance of ideas and actions that are “supposed to represent'; a better way of life. Throughout the book there are many examples of hatred and evil undermining what sounds like a great utopia when introduced, but not when they are lived. The ideas are very familiar because they are based on those that drove the Russian Revolution, and what went wrong with it. The difference between a nice Utopian idea and what goes wrong in real life has to do with human nature. Greed is real, in that it drives people to do things. There is greed for power, greed for food, and greed for whatever a greedy person might want. While not everyone is greedy, some people are very much so. The very greedy people make life difficult for the rest of us. This is not such a big problem in democracies, which are constructed to balance any action with the ideas of many groups and rights. In a dictatorship, like the Soviet Union, a person like Stalin can determine every key aspect of most individuals’ lives. The more violent a Stalin is, the more power a Stalin has; and the farther from Utopia are the lives of the common people. Napoleon’s ideas and actions in Animal Farm were similar to those first of Lenin and later of Stalin during the development of the Soviet Union, which resulted in the deaths and terror that deeply affected the lives of tens of millions of Soviet citizens. For example, Napoleon had made other high-status animals confess to things they had never committed. When the eggs of the three hens were crushed really by Napoleon’s dog, they were forced to confess, “…Snowball had appeared to them in a dream and incited them to disobey Napoleon’s orders'; (93). The dogs were then murdered, making Napoleon the only ruler. Even though Napoleon clearly killed the hens’ eggs, they still confessed to something that was untrue, which made Napoleon’s “appearance'; better to those who had no direct knowledge of the incident. Joseph Stalin had appointed government officials, controlling their income, what they said, and of ten their death. Soon he made them confess to things that were untrue, such as being spies. Government officials were exiled, thrown in jail, or killed. Soon Stalin was the one, true ruler of

Physics of an Mri Machine

The Physics of an MRI Machine. Whitney Wright PH106/006 Dr. Probst 06/05/2012 The Physics of an MRI Machine There are many physical concepts used in a Magnetic Resonance Imaging, also known as MRI, machine. There are many physical concepts used when an MRI is taken of the body, such as; radio waves, resonance and pulse sequences, magnetic fields being produced and lastly, magnets. Radio waves much stronger than the magnetic field of the Earth are sent through the body which causes the nuclei in the body to move to a different position.When the nuclei move back to the place they originated from, they send back radio waves that the scanner on the machine picks up and turns them into a picture. Resonance is very common within multiple branches of physics, without resonance we wouldn’t have television, music or radio. Resonance is also one of the most unexplained phenomenons in physics; it causes glass to break with a high pitched voice, bridges to collapse and also earthquakes ca using buildings to collapse.Within the MRI, nuclear magnetic resonance is used, this is when magnetic fields and radio waves cause the atoms in the body to give off tiny radio waves (Bellis). The explanation of Pulse sequences are defined in a basic way by the article â€Å"MRI Physics: pulse sequences† as ‘the pulse sequences define the manner in which the radiofrequency pulses, which generate the detectable signals, and magnetic field gradients, which provide the spatial encoding of the signals’ (Sharma). When the pulse sequences are used a sequence diagram is used to show how the sequences will occur during the MRI.There are many different sequences available; each used for creating certain images, the most commonly used is the spin echo sequence. When magnetic fields are produced, it means an electron has moved along a wire creating a magnetic field around that electron. When the wire is in the form of a loop, or multiple loops in this case, a very large magn etic field is produced and it runs perpendicular to the field. The magnets within the MRI are known as the primary magnet and the gradient magnets. The primary magnet or permanent magnet is the coiled wire that creates the magnetic field.These coils have to be stored at -450( Fahrenheit within a type of liquid helium. These magnetic fields are between 10,000 and 30,000 times stronger than the magnetic field of Earth. The gradient magnets consist of three smaller magnets within the MRI machine. These magnets are about 1/1000 as strong as the primary magnet and allow smaller images of the area to be produced. These magnets help focus on a particular part of the body (Cluett). There are many other physical concepts that I did not discuss used within the MRI machine.The main concepts are radio waves, resonance, pulse sequences, magnetic fields being produced and magnets. Works Cited Bellis, Mary. â€Å"Magnetic Resonance Imaging MRI. †Ã‚  About. com, Investors. New York Times Com pany, n. d. Web. 5 June 2012. . Cluett, Jonathan. â€Å"MRI: What is a MRI?. †Ã‚  About. com, Orthopedics. New York Times Company, 15 Aug. 2011. Web. 5 June 2012. . Sharma, Harish, and Jim Lagopoulos. â€Å"MRI physics: pulse sequences. †Ã‚  Acta Neuropsychiatrica  22. 2 (2010): 90. EBSCOhost. Web. 5 June 2012. .

Management Assignment: Human Intelligence Essay

Traditionally organisations have concentrated upon the intelligence of individuals and held the point of view that intelligent people in terms of IQ succeeded more. However, these ideas are continually challenged by the idea of emotional intelligence being key indicators of management performance (cited in Khosravi, Manafi, Hojabri, Aghapour and Gheshmi, 2011, pg 3). Emotional intelligence is ones ability to perceive and regulate other people’s emotions (cited in Sadri, 2012, pg 536). In present society, emotional intelligence of management is essential to positive communications in projecting ideas, increasing value of teams through creating common team values and hence increasing the job satisfactions of individuals in workplaces from corporations to sales. Emotional intelligence is consequently directly related to the overall performance of a company and also the efficiency of individual employees. It can also be said that emotional intelligence is much more important then pure intelligence in shaping leadership success (cited in Sadri, 2012, pg 537). Managers use communication as a method to transfer meaning to others for the ultimate purpose of achieving their goals and objectives. The ability to communicate efficiently depends upon the manager’s capability to empathise with his or her peers, that is, the manager’s level of emotional intelligence. Goleman’s study asserts the notions of emotionally intelligent individuals are more successful at communicating their ‘ideas, goals and intentions’ (cited in Zeidner, Matthews, Roberts, 2004, pg 386). Similarly, Wasielewski’ studies suggests emotionally intelligent individuals are able to ‘excite and enthuse’ or make others ‘feel cautious and wary’ (cited in George, 2000, pg 7). This sort of behavior will consequently motivate or demotivate individuals in the workplace. Thus emotional intelligence is crucial as it allows managers to communicate effectively and therefore achieve his or her goals by influencing the mood and emotion of his or her team. Bar On further asserts that managers are also able to use communication to ensure a positive result in environmentally demanding work situations (cited in Zeidner, Matthews, Roberts, 2004, pg 374). Managers will only be able to do this if they understand their employees’ personal feelings, hence emotional intelligence is the tool that lets managers communicate effectively in any sort of situation. Regardless of whether the situation is difficult or not, emotional intelligence will always be significant because it allows the manager to communicate effectively with his or her employees (cited in George, 2000, pg 8). A consequence of managers who communicate with high emotional intelligence creates value adding member interaction, which in turn increases team productivity. Positive emotions of certain individuals such as managers can influence team member mentality and is high likely to increase group cohesion through relationship building, this is also known as positive ‘emotional contagion’ (cited in Ashanasy and Daus, 2002, pg 79). However oppositely, negative emotions of an individual can decrease the efficiency of other team members since negative attitudes can ‘infect’ co-workers and is hard to reverse (cited in Ashanasy and Daus, 2002, pg 79). Consequently due to these polar outcomes the need for emotionally intelligent managers is crucial to the operation of a team to complete tasks efficiently. More importantly, high emotional intelligence can impact a leaders and teams ability to construct team goals and objectives (cited in Ashanasy and Daus, 2002 pg 81). This is asserted by Rosete and Ciarrochi study in which concluded that high emotional intelligent leaders performed more efficiently and was not affected by cognitive ability (cited in Sadri, 2012, pg 538). Apart from leadership highly emotional intelligent team members also increased team efficiency. A Study by Jordan and Troths concluded this through their experiment where they concluded high emotional intelligent team members performed more exceptional then low emotional intelligent teams (cited in Sadri, 2012, pg 538). Thus leadership through high emotional intelligent individuals increases the value of a team, however high emotional intelligent team members also contribute to positive team interaction. Another aspect of high emotional intelligent leaders is improved job satisfaction and hence increased performance. Emotionally intelligent leaders are able to influence ‘shared beliefs’ of groups, allowing them to shape ones abilities and skills to communicate and co-ordinate with each other (cited in Zampetakis and Moustakis, 2011, pg 84 ). These ‘shared beliefs’ allow groups to have high job satisfactions due to improved performance due to positive emotional norms created by the manager (cited in Zampetakis and Moustakis, 2011, pg 84). Henceforth, an increase in group job satisfaction will allow individual satisfaction growth, this will in turn increase overall efficiency. In the studies of Ashkanasy and Daus, we can also view the importance of emotionally related job satisfaction. The study contains scenarios, which stress how negative satisfaction partly due to leadership problems can have adverse affects upon other team members. Research has also exemplified the need for emotionally intelligent managers to heighten positive emotions with employees particularly in the sales industry to increase customer rentention (cited in Ashkanasy and Daus, 2002, pg 77). Hence, job satisfaction is highly correlated with the emotional intelligence of managers. Job satisfaction is clearly an important factor in the workplace as it is able to increase efficiency. As organisations and businesses seek to increase efficiency, the use of emotionally intelligent individuals will be employed to redefine groups and individuals in the workplace. Over time as stronger evidence builds upon that high emotional intelligent individuals make better leaders, companies will undergo a transition to recruit or train emotionally intelligent individuals. As companies continually gain knowledge in this field, competitive strategies will be formed to better firm performance. As they embrace these types of changes, competitive advantages particularly in the sales industry will experience large competitive advantages. Communication from highly emotionally intelligent allows more positively regulated team ambitions and hence allow greater team collaboration, which increases inter-personal relationships. Team collaboration is highly effective in producing superior job satisfactions and consequently job efficiency. Hence, emotional intelligence is essential for leaders to manage successfully in workplaces. References: Sadri, G. , (2012). Emotional intelligence and leadership development, Public Personnel Management, Vol. 41 No. 3, pp. 535-548 Date Viewed – 10 April 2013 <http://web. ebscohost. com. wwwproxy0. library. unsw. edu. au/ehost/detail? vi d=3&sid=7e41ae83-e0b2-455b-ac25-1568e4f33f6f%40sessionmgr110&hid=112&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=buh&AN=79656429> Khosravi, R. D. , Manafi, M. , Hojabri, R. , Aghapour, A. H. , Gheshmi. R. , (2011). The relationship between emotional intelligence and effective delegation. International Journal of Business and Social Science, Vol. 2 No. 19, pp. 223-235 Date Viewed – 10 April 2013 lt;http://search. proquest. com. wwwproxy0. library. unsw. edu. au/abiglobal/docview/904526890/13D5FC8D9CD73AEC7F5/1? accountid=12763> Zeidner, M. , Matthews, G. & Roberts, R. D. , (2004). Emotional Intelligence in the Workplace: A Critical Review. Applied Psychology, 53(3), pp. 371–399. Dated Views – 10 April 2013 <http://online library. wiley. com. wwwproxy0. library. unsw. edu. au/doi/10. 1111/j. 1464-0597. 2004. 00176. x/abstract;jsessionid=BC2DC14C7B9282FD9361B666E034A2C9. d02t02> George, J. M. , (2000). Emotions and Leadership: The Role of Emotional Intelligence. Human Relations, 53(8), pp. 1027–1055. Date viewed – 10 April 2013 <http://search. proquest. com. wwwproxy0. library. unsw. edu. au/docview/231437575/fulltextPDF? accountid=12763> Ashkanasy, N. M. & Daus, C. S. , (2002). Emotion in the workplace: The new challenge for managers. The Academy of Management Executive, 16(1), pp. 76–86. Date viewed – 10 April 2013 <http://www. jstor. org. wwwproxy0. library. unsw. edu. au/stable/4165815> Zampetakis, L. A. & Moustakis, V. , (2011). Managers’ Trait Emotional Intelligence and Group Outcomes: The Case of Group Job Satisfaction. Small  Group  Research, Vol. 42 No. 1, pp. 77-102 Date Viewed – 10 April 2013

What You Need to Know About Changing Careers With Expert Norine Dagliano

What You Need to Know About Changing Careers With Expert Norine Dagliano If you’re looking for a job, you probably already know about Norine Dagliano. A coach and hiring expert who writes  on  ekm Inspirations, Norine shared with us some insight into how to find a job and use job boards to help. What are some common motivations you see among people changing careers?I’ve worked with thousands of career changers; some are motivated by ambition, others by circumstances.Divorce, death of a spouse, changes in health, company lay-offs, or other life circumstances â€Å"motivate† people to examine where they are and decide to pursue another path.On a more positive note, there are professionals who retire, but are not ready to quit working. They  want to step back from a high-power career to move into an area with fewer pressures or pursue an earlier dream that got pushed to the back-burner. Veterans leaving a career in the military find themselves asking, â€Å"Now what?†- many military occupations do not translate to the privat e sector, so clearly a career change is in order.Then there are those who are motivated by sheer ambition and a belief that anything is possible- these are the job seekers that embrace change and go after it with gusto. Some have decided to go back to school and pursue a degree in a new field. Others have never let go of their dreams to work for themselves and have the confidence and support- emotional and sometimes monetary- to proactively plan a change and chart a course to make it happen.What’s the future of the career? Will we stick to one job still, or is the future in multiple careers?The career ladder is no longer a reality, nor  is the notion that one will have one job and one employer until he or she retires. Careers no longer follow straight lines; instead, they zig and zag, stop and start, step back and then forward.Forecasters predict that the average 21-year-old entering the workforce will make three to five career changes before leaving the workforce. Factor i n the reality that dozens of new occupations are introduced each year, and it only stands to reason that what one is doing now may not even be around in a few years or may take on a whole new look. Employers who are not willing to embrace this new workforce and recognize that knowledge, skills, and abilities often outweigh experience will overlook valuable talent and, in turn, fail to thrive.

Study into Drug discovery and Design The WritePass Journal

Study into Drug discovery and Design Introduction Study into Drug discovery and Design Introduction1. Background1.1 Target Identification and Validation1.2 Hit Identification and the Generation of a Lead Series 1.3 Lead Optimisation 1.4 Summary and Aims2. Case Studies2.1 Nuclear Magnetic Resonance in Fragment Based Library Screening and X of A G-Protein Coupled Receptor3. Conclusion3.1 Summary of Main Points and Advantages of Structure-Based Techniques3.2 The Limitations of Structure-Based Techniques3.3 Concluding Thoughts and Future AdvancesRelated Introduction 1. Background Drug discovery and design is fuelled by the need for appropriate and effective treatment for disease. Initially discovery was achieved via empirical screening of vast libraries of molecules, which was incredibly effective. The majority of drugs currently in clinical use were discovered this way. However with increased technology, and a greater need for newer more effective medicines, structural biology has become a prominent tool. The general principles behind drug discovery briefly discussed here include target identification and validation, and hit discovery or design to generate a lead which is then optimised. 1.1 Target Identification and Validation A target is often a protein, however it can also be RNA, DNA or a carbohydrate. People who suffer degenerative, autoimmune and genetic diseases can be screened for genetic differences through genome wide association studies (Grupe et al., 2007)or systematic meta-analysis (Bertram et al., 2007). Infective organisms have genes that are very different to human genes that may be essential in the life or infective cycle of the organism and are thus useful targets that can be identified through bioinformatics analysis or loss of function mutant phenotype studies (Crellin et al., 2011). A structure-based technique includes structural genomics, which is the study of the structures of all proteins in a genome. 1.2 Hit Identification and the Generation of a Lead Series Once a target has been identified and validated, small molecules that bind and in some way alter function must be discovered or designed, again there are a number of ways in which this can be done. Empirical screening has identified a number of drugs, however structure-based techniques are more and more commonly being used. 3D structures from X-ray crystallography data and, to a lesser extent, nuclear magnetic resonance (NMR) have been used to generate the information required for computational methods involving docking and screening. This has been useful, for example in the in-silico screening of G-protein coupled receptor (GPCR) binding molecules (Richardson et al., 2007), however most structure-based drug designs have come from the design of compounds based on the 3D structure obtained from X-ray crystallography or NMR, or via biophysical screening techniques involving surface plasmon resonance (SPR) or NMR. Structure based screening methods often require fragment based libraries. These encompass a greater number of potential molecules, within smaller libraries of compounds, this is possible because there are no large functional groups that would inhibit binding, and so result in attractive starting points for hit discovery (Nordstrà ¶m et al., 2008). To validate or measure the properties of the hits, crystal structures can be evaluated and additional information from secondary SPR screens, thermal information from isothermal titration calorimitry (ITC), and differential scanning fluorimitry (DSF) can be used to complement the data (Retra et al., 2010). 1.3 Lead Optimisation Once validated, the structure is optimised. This can be based on ligand binding structures in NMR and X-ray crystal structures, or increasingly, in-silico modelling based on the pharmocophore hypothesis involving the evaluation of chemical and functional groups that may bind important sites of the target molecule (Voet et al., 2011). The key structural techniques involved in structure-based drug design are X-ray crystallography and NMR, though mass spectrometry can also be used to observe proteins in multi-protein complex interactions. X-ray crystallography generates 3D structures of the protein of interest from crystals generated by altering conditions such as buffers, pH, temperature and the format; nanodrop, hanging drop as well as others (Giegà © Sauter, 2010). These crystals are homogenously packed and stored in cryo-protecting buffers so that they can be stored in liquid nitrogen which protects them from the X-rays used to generate the 3D structural information (Philippopoulos et al., 1999). Once obtained, if the ligand of interest is soluble and has relatively high affinity for the target protein, co-crystallisation studies can be used to look at interactions of the different ligands of interest with the target protein. This is not always possible; however there have been improvements since the advent of fragment based libraries. NMR based structures are more time consuming to construct, requiring the analysis of NMR peaks of different spectra to associate them with specific nuclei to generate restriction information to produce a structure. Though more time consuming, it is incredibly useful if other forms of structural information are not available (Zou, 2007). In structure-based drug design NMR has been more useful in ligand protein interaction studies (Pellecchia, 2005), but has also been used in screening libraries for hit molecules (C. Murray et al., 2010). Mass spectrometry can be used in each stage of drug discovery (Deng Sanyal, 2006), especially as technology advances, however it is much more limited (justification?) than those methods or techniques already mentioned and so will not be discussed in any great detail. To complement these techniques there are a vast array of technologies available, a few of which are   mentioned below. SPR measures interactions between the target protein and potential hits in biosensors, and can also be used in hit validation and optimisation in secondary screens (Retra et al., 2010). Since fragment based screening, SPR has become much more popular and will be discussed in greater detail later. Other complimentary techniques involves ITC which measures entropy and enthalpy to determine their contributions in ligand interaction, and therefore gives a clue as to what sorts of alterations would be required to optimise binding. DSF is also widely used, more often to measure where the hit compound is binding on the target molecule (Domigan et al., 2009). 1.4 Summary and Aims To summarise, the stages of drug design include target identification and validation; hit identification and generation of the lead molecule; and then the optimisation of the lead into a drug for testing and then clinical trials. Target identification may utilise such structural techniques as structural genomics. Hit identification makes better use of structural information from X-ray crystallography or NMR and the design of drugs and computational in-silico drug design, or screening methods including high throughput screening (HTS), SPR library screens, and in silico computational screening methods. Optimisation generally uses structural information taken from X-ray crystallography as well as computational methods and in some cases NMR aided by SPR, DSF and ITC to increase binding affinity and then the pharmacokinetic properties. To assess their usefulness in structure-based drug discovery and design, case studies will be analysed to look at how these techniques have been used to further the production of clinically used drugs, or at least increase our understanding so that we may be able to use it in future drug design attempts. 2. Case Studies 2.1 Nuclear Magnetic Resonance in Fragment Based Library Screening and X-ray Crystallography in the Design and Optimisation of Hsp90 Inhibitors The heat shock protein 90 (Hsp90) is a human chaperone which is involved in stress responses, but is also required in the essential process of client protein maturation. Many of its client proteins are involved in cell signalling, proliferation and growth (Biamonte et al., 2010), which have been associated with a number of different cancers. The overexpression or inappropriate activation of Hsp90 is also therefore associated with cancer, therefore a number of drugs have been produced which aim to inhibit the essential ATPase activity of Hsp90. Hsp90’s combinatorial in so many different client proteins makes it a good target for drug development, therefore many drugs are already available that target Hsp90. However there are a number of problems concerning bioavailability, toxicity and increased resistance and so newer more effective drugs are required (Van Montfort Workman, 2009). As can be seen in figure 1 Hsp90 is active as a dimer, and in the N terminal of each subunit is a functionally essential ATPase site (Prodromou et al., 1997), the middle domain regulates the interaction of Hsp90 with its client proteins (Meyer et al., 2003) and the C terminal region is responsible for dimerization (Minami et al., 1994). Initially drugs for Hsp90 were discovered using the binding and cell based assays, however more recently there have been drugs that have entered clinical trials that were generated using structure-based techniques. These have targeted the ATP binding site essential for function, and so required a good understanding of this site. As can be seen in figure 2 there are critical hydrogen bongs between the adenine of the ATP bound, and the side chain of the amino acid residues Thr184 and Asp93 . These would therefore be ideal targets in the design of an inhibitor molecule (Obermann, 1998). There are examples where inhibitors have been identified using NMR and X-ray crystallography screening methods of fragment libraries, and as has been described, fragment based libraries generate useful starting hits (Hartshorn et al., 2005). In an NMR fragment based library scan, the displacement of low concentrations of ADP (the product compound of the ATPase domain)was measured using NMRwaterLOGSY (Water-Ligand Observed Via Gradient SpectroscopY) (Dalvit et al., 2001), which indicated when a fragment had bound which could be chosen for further study (Murray et al., 2010). Murray et al. discovered a number of binding fragments, 2 of which became lead compounds. The first was compound 1 (fig3) which made extensive hydrogen bonding interactions with key residue Asp93 (as seen in figure 2) and a number of water molecules found deep within the binding pocket as can be seen in figure 4a. However, as can be seen in figure 4b the compound 1 doesn’t efficiently fill the lipophilic pocket defined by the residues Met98, Leu107, Val150, Phe138 and Val186, additionally it was found that compound 1 wasn’t particularly stable, as it was twisted about the bond between the pyridine and pyrimidine. Virtual screening for analogues was used initially to produce more stable forms of compound 1, and though this yielded higher affinity binding molecules, their torsion profiles indicated steric clashes between the methoxy group at position R2 (fig5a) would result in unfavourable binding. Instead using SAR (specific absorption rate) analysis, it was predicted that exchanging the methoxy for chloro improved it significantly, resulting in compound 9, the basis of further optimisation outline as a chemical structure in figure 5b, with the positions for optimisation labelled as R4 and R5. This was done using computer based modelling techniques, and illustrates how useful it can be when enough information regarding the target protein and the current ligands is available. The methoxy and chloro groups added to positions 4 and 5 of the upper phenyl ring increased binding affinity to the lipophilic binding pocket to 12nM. Once the affinity was increased, cellular activity had to be improved and this was achieved by adding a morpholine group to position 5 outlined in figure 5b, a decision based on the crystal structure, and this resulted in compound 14 which is currently going through clinical trials for the treatment of different cancers. As can be seen in figure 6, compound 14 in blue binds in much the same way as compound 1 in orange, but makes more extensive interactions with the lipophilic pocket via an extended phenyl ring. The second line of lead compounds Murray et al. followed initiated from compound 3 (fig7), which using their initial NMRwaterLOGSY screening method appeared to bind rather inefficiently. However, upon observation of the X-ray crystal structure of Hsp90 bound to compound 3 (fig8) it was decided that it provided a quick and attractive optimization route. It’s binding with water molecules and one of the key residues Thr184, though on its own provided a relatively weak interaction, if optimised could also make direct interactions with the alternative key residue Asp93, and also with additional endogenous water molecules. Using trial and error, the writers found that a tetra-butyl group filled the lipophilic pocket appropriately with fewer steric clashes, and this resulted in compound 18, the lead compound that was further optimized to make more effective interactions within the lipophilic pocket. Using modelling studies, interactions with the side chain of residue Lys58 was approved. Compound 24, an isoindoline filled the pocket with a phenyl ring which interacts with residues Ala55, Lys58 and Ile96 completely displacing Lys58 side chain as can be seen in figure 9a. In other inhibitors a position 2 OH (hydroxyl group) resulted in the greater affinities, however compound 18 had a position 4 OH, and a replacement with an OH at position 2 resulted in a lower affinity compound. Addition of an OH at position 2 to compound 24 as well as the OH at position 4 resulted in compound 31 which enabled interactions directly with Asp93, retaining interactions with Thr184 as well as increasing hydrogen bonding with water molecules as can be seen in figure 9b. It also , illustrates compound 31 in blue binding in much the same way as compound 3, but it fills the lipophilic pocket more efficiently, and makes more extensive interactions. This greatly increased binding affinity and compound 31 is now going through clinical trials. This helps illustrate the importance of structure-based approaches such as NMR and X-ray crystallography in the identification and optimization of lead compounds, as well as the input computer based methods can have. X-ray structures were particularly helpful in the case of compound 3, as without this structure compound 3 would have been dismissed as an inefficient binding compound. Additionally, all kinetic data which helped support the optimization and validation steps, was obtained using ITC. Further work on improvements to the pharmacokinetic properties as well as drug-tissue distribution should be concentrated on. 2.2 Crystal Structures from X-ray Crystallography and Nuclear Magnetic Resonance in In-Silico Drug Design, and 3D Drug Development Human Immunodeficiency Virus HIV (the human immunodeficiency Virus) is the causative agent of the acquired immune deficiency syndrome (AIDS) and statistics show that by 2005, approximately 38 million people worldwide were living with HIV (Beyrer, 2007). HAART (highly active anti-retroviral therapy) established in the 1990’s makes living with HIV bearable by keeping viraemia low, and CD4+ (cluster of differentiation 4) cells at a high enough level to protect from opportunistic pathogens. However, with increasing resistance and the negative side effects of current drugs, constant improvement and newer drugs are required. The protease inhibitors were revolutionary in HIV treatment, starting with the rationally designed Saquinavirapproved for use in 1995 (Roberts et al., 1990). HIV protease is a good target, essential in the life cycle of the virus, and though Saquinavir was very successful, resistance quickly arose, and so a greater understanding of the protease structure and biochemistry was required. This was necessary not only to try and target residues that would be less likely to result in resistance, but also to improve the pharmacokinetic properties, producing non-peptidic as opposed to peptidic drugs to reduce toxicity and improve half-life (Arung Ghosh et al., 2008). There have been multiple inhibitors designed with the use of X-ray crystallography, to enter clinical trials and be approved by the FDA (food and drug administration) for use in HAART. It was determined that by targeting the protease backbone residues, it would be possible to generate drugs that would be less likely to result in resistance because mutations are rare, and those that occur do not often distort the overall conformation. Such a site is therefore more conserved and a better drug target (Ghosh et al., 2011). Saquinavir, though a peptidic drug with poor pharmacokinetic properties did bind the backbone resides (though relatively weakly) it also bound outside of the binding envelope, the region which locates the gag-pol polyprotein for cleavage. Mutations are far more common and tolerated outside of the envelope region. Mutations would therefore not reduce virion viability but would prevent inhibitor binding (King et al., 2004). The development of Aprenavir, with a single-ringed tetrahydrofuran (THF) group was designed using Saquinavir as a scaffold, to generate a related, but non-peptidic cyclic compound that would bind and inhibit the active site of the protease, much in the same way as Saquinavir but with increased half-life, better pharmacokinetic properties, increased backbone binding and a more specific binding to the active site envelope. The chemical structure of Aprenavir as seen in figure 9, binds the S1S2 S1’S2’ binding envelope of the protease, closely interacting with the backbone residues Asp29 and Asp30, as well as many other residues (Kim, 1995). The interactions with Asp29/30 were relatively weak, and the THF group, believed to be involved in increasing favourable enthalpy interactions, if increased in size was thought to be able to improve backbone and hydrophobic interactions with the residues that make up the lipophilic flap. Using Aprenavir as a scaffold, Darunavir was developed, a bis-THF compound with a double ring, as can be seen in figure 10. This single ringed to double ringed evolution resulted in more extensive interactions with the key backbone residues (Tie et al., 2004) as can be seen in figure 10, as there are far more hydrogen bonds present between the bis-THF complex in pink with the backbone residues than there are between the single ringed THF complex in green. To measure the ability of Darunavir to withstand mutations in HIV protease, Tie et al. co-crystallised Darunavir with a wild type protease and a mutant version. As can be seen in figure 11, the wild type hydrogen bonds at 4.1 Ã… indicated by the purple dashed lines   is retained in the mutant distance of 3.8 Ã… in blue. This suggests that Darunavir is robust, and will continue to be active against resistant strains of HIV. The inherently high mutation rate of the HIV genome due to the accident prone polymerase means that there will be strains that will become resistant to Darunavir in the future, and it is always necessary to stay one step ahead. Darunavir has thus been used in modelling studies to design optimised structures which are incredibly potent, more so than Darunavir retaining the favourable pharmacokinetic and cellular properties (Ghosh et al., 2011). Figure 12 details the position of compound 1b in green– a Darunavir like compound in the hydrophobic pocket of the HIV-1 protease, and as can be seen, it makes a number of Van der Waals interactions with residues Ile47, Val32, Il84, Leu76 and Ile50’ which make up the hydrophobic flap as well as hydrogen bonds with Asp30 (3.5Ã… long) and Asp29 (2.9Ã… long). To improve the interaction distance with Asp30’s NH group, Ghosh et al. modelled an increase in phenyl ring size of the P2 ligand   in an attempt to also increase flexibility of the structure. This was achieved with the addition of an amide group which also increased the hydrophobic interactions with the lipophilic pocket residues. The pink structure of compound 35a as seen in figure 12 binds in much the same way as compound 1b, but makes more extensive interactions with the key residues and fills out the lipophilic pocket more effectively. This compound was then generated and its Ki and IC50 values cal culated to measure it against 1b, it was a far more efficient inhibitor, and thus a potential clinical candidate. There are many examples of proteins that cannot be crystallised, and to obtain structural information so rather than using X-ray crystallography, NMR can be used. As an example, the HIV protease structure was constructed using NMR (fig 13).An X-ray crystal structures is a static representation of a dynamic system in a relatively unnatural environment, whereas NMR is in solution and is believed to be more biologically relevant, and can in some circumstances be used to observe dynamic protein systems (Zou, 2007). NMR is far more time consuming however, and the inherent flexibility of proteins results in areas of low resolution in structures, more so than with X-ray crystallography. NMR has been used more successfully in hit identification, as has been discussed in the example of Hsp90 inhibitors. 2.3 The use of Surface Plasmon Resonance, Isothermal Titration Calorimetry and In-Silico Drug Design to Complement Structural Techniques Such as X-Ray Crystallography and Nuclear Magnetic Resonance As technology improves newer methods have evolved that complement the existing, this includes such techniques as SPR which detects the interactions between the target protein and ligand, used in primary fragment based library screens to identify hits, or secondary screens to identify or validate hits (Retra et al., 2010). As previously discussed, fragment based screening methods can result in attractive starting points for lead optimisation (Erlanson, 2006). SPR can be used in a number of ways, in chemical micro arrays, SPR imaging, secondary screens of hits found through high throughput screens and also in primary biosensor screens. In primary screens, a biosensor is set up with the target molecules immobilised on chips and this has been successfully used in the identification of hits without the requirement of other forms of structural information (Nordstrà ¶m et al., 2008). The hit molecules can then be integrated into lead series and optimised using other structural techniques such X-ray crystallography and NMR to obtain clinical candidates (Huber, 2005). The matrix metalloproteinases (MMPs) are a group of proteins found in many different species; in humans there are approximately 12 that are involved in tissue remodelling, and degrading extra cellular matrix molecules such as elastin, collagen and laminin (Demedts et al., 2006). MMP-12, involved in various human diseases such as emphysema and chronic obstructive pulmonary disease (COPD) is the target of a number of therapeutic drugs, all of which have harmful side effects and so new drugs are required (Nordstrà ¶m et al., 2008). Using SPR and ITC in conjunction with NMR or X-ray crystal structures Nordstrom et al. produced an in silico drug design based on the binding sites identified by the crystal structures, using pharmacophore properties to model a binding molecule. Mutant proteins were designed in silico and then generated, immobilised on chips along with wild type proteins as depicted in figure 14.   Molecules designed in silico could then be screened against the different p roteins on the chip. For screening purposes SPR is limited, the number of molecules screened against the biosensor is relatively small as the proteins become degraded; only a couple of hundred molecules can be screened, compared to thousands in HTS.   The library must therefore be carefully designed, using in silico modelling, docking and screening, or with a vast knowledge and understanding of the target. Alternatively, SPR can be used in hit validation for lead series initiation, assessing the enthalpy and kinetics of binding, as was the case for capstatin analogues to increase binding affinity for C3b in the treatment of multiple human disorders involving the over-activation of complement (Qu et al., 2010). C3b is an appropriate target because it is involved in so many disorders such as neurodegenerative, sepsis and has also been linked to stroke. Campstatin is a good peptidic protein inhibitor, binding and inhibiting C3b regardless of the initiation pathway. However, due to its peptidic nature, Campstatin is not very stable with a short half-life in vivo, and due to the low concentrations of C3b found in plasma, a higher affinity compound with better pharmacokinetic properties would be ideal. N-methylations were analysed at different positions on the Campstatin scaffold and changes in binding affinity measured using SPR, and confirmed using ITC to conclude that by generating a compound that retains a rigid structure both in solution and in a bound state, it would bind with increased enthalpy, without decreasing the entropy as had other previous designs (Qu et al., 2010). This demonstrates the powerful applications SPR and ITC can have in drug discovery or design, and how in conjunction with in-silico computer based techniques, they can complement X-ray crystallography and NMR techniques. 2.4 The Difficulties Associated with Membrane Protein – The B2 Adrenergic Receptor: an Example of A G-Protein Coupled Receptor Crystallisation seems to be at the heart of structural biology   and even with the option of NMR there are still severe limitations that mean many proteins, particularly membrane bound proteins, cannot be crystallised   and thus cannot be visualised as a 3D structure. This is particularly problematic for structure-based drug design, as some 50% of drugs target G-protein coupled receptors (GPCRs) alone, not including the many other families of membrane bound proteins.   GPCRs are a superfamily of proteins which all have 7 transmembrane helices found in eukaryotes important in many crucial signalling processes (Lundstrom, 2005). The problem with studying membrane proteins in general is the difficulties in solubilising them and getting enough protein to work with. To obtain this large amount of protein, recombinant protein is required and for human protein this is a particularly difficult task (Mancia et al., 2007). The lack of structural information limits our understanding of ligand binding, as well as allosteric control and active site location (Summers, 2010).   There have been major advances in obtaining the structures of GPCRs recently, with structural information on rhodopsin, A2A adenosine receptor, B1 adrenoreceptor and the B2 adrenergic receptor.   The problems to overcome were obtaining enough usable protein, thus an appropriate expression system, the intrinsic flexibility and therefore excessive instability, and obtaining the exact solubilising formula for each protein. Once achieved, the crystallisation process for membrane proteins is no different than for globular proteins (Velipekka et al, 2010). To stabilise the different GPCRs, mutagenesis was used in rounds for B1 adrenoreceptor (Warne et al., 2008), or in the case of the B2 adrenergic receptor and A2A adenosine receptor, the flexible intracellular loops were stabilised by replacing them with the easily crystallised and inherently stable T4 lysozyme (Rosenbaum et al., 2007). Therapeutics aimed at A2A adenosine receptor could help in the treatment of seizure, asthma, Parkinson’s, pain and many other neurological problems (Jaakola et al., 2009). The crystal structure of the A2A adenosine receptor with the antagonist ZM241385 enabled the determination of important residues in ligand binding, and thus generated the information required to use computational modelling studies to suggest residues that would be important in inhibitor binding. Figure 15 depicts the binding of the antagonist, hydrogen bonded to Asn253, aromatically stacked against Phe168 as well as hydrophibically interacting with Ile274. An understanding of these interactions greatly helps in the elucidation of therapeutically important binding molecules ( Jaakola et al., 2009). B2 adrenergic receptors, a class of GPCR are important in smooth muscle related diseases such as asthma (Cherezov et al., 2007). Cherezoc et al. made a B2-adrenergic receptor T4 lysozyme fusion protein to enable crystallisation with Carazolol at 2.4Ã…. Carazaole has high affinity for the receptor, lying adjacent to, and making significant interaction with the residues Phy289, phe290 and Trp286 as seen in figure 16b and reduces basal level of activity of the receptor via its interactions with phe289/290 which result in the inactive trp286 state as seen in figure 16. This understanding of agonist binding and an in depth knowledge of the residues involved, if expanded upon could increase the possibilities for structure-based drug design and modelling. 3. Conclusion 3.1 Summary of Main Points and Advantages of Structure-Based Techniques The power of structural biology is apparent; it provides a clear physical picture of the target protein. It enables the identification of hit compounds via X-ray crystallography and more commonly NMR, supported by the complimentary techniques – computational analysis, SPR, ITC and DSF. Such techniques can validate those hit compounds to enter them into lead series and they can then be used to optimise leads to generate clinically usable compounds. The importance of structural biology is therefore easy to see as it has been successful in generating clinically used drugs, Darunavir for the treatment of HIV as a protease inhibitor being just one of many examples. 3.2 The Limitations of Structure-Based Techniques Of course they are not without their limitations. X-ray crystal structures are static freeze frame shots of a dynamic system, so we cannot be certain that what we see is biologically relevant or simply artefacts. Both X-ray crystallography and NMR suffer with the inherent instability and flexibility of proteins. There are methods to improve the 3D structures, as seen in the crystallisation of membrane protein – the B2 adrenergic receptor (Rosenbaum et al., 2007), suggesting that these limitations are not permanent, and can be overcome. Many proteins cannot be crystallised, and though there has been recent breakthroughs as with the case of the GPCRs, the vast majority have not been visualised and yet 50% of drugs are aimed at them. Complementary techniques such as SPR, ITC and DSF have successfully been used to identify hit molecules (Nordstrà ¶m et al., 2008) and to validate or optimise leads (Huber, 2005). Unfortunately these too are not without their faults, requiring smaller screening libraries, and the proteins involved to be constantly replaced during screens. To overcome this there have been computer based in-silico screening and design processes, which under certain circumstances has been used efficiently as was the case with the optimization of Darunavir (Ghosh et al., 2011), however there have been huge limitations. The first human GPCR crystallised, rhodopsin was a model for all GPCRs and in-silico modelling studies utilised it to generate binding molecules, but with the visualisation of the A2A adenosine receptor via X-ray crystal images, it became apparent that this was a far too over-simplified view ( Jaakola et al., 2009). 3.3 Concluding Thoughts and Future Advances To conclude, there are clear limitations concerning the structure-based design of therapeutic drugs, requiring further advances in technology and understanding to be made before we can easily utilise every form of technology efficiently and in an integrated fashion. Structure-based techniques do not speed up the process of drug discovery, however, there are also clear advances that have been made through the use of such structural biology techniques. They should therefore continue to be used in conjunction with current technologies to ever improve the therapeutics in use. Future advances should include improved recombinant protein technologies and purification procedures to obtain the large quantities of protein required, improved detergent mixtures for membrane proteins as well as better crystallisation procedures in general to increase resolution. As well as finding hits for lead series of molecules, structural techniques should also focus on increasing the number of targets, so that whole new sets of drugs can be made to add to combinatorial drug therapies such as HAART in the treatment of HIV, in an attempt to overcome the problems of resistance.