Introduction and Historical Perspective

Vijay Kumar lliakur and Manju Kumari Thakur (eds.) Handbook of Polymers for Pharmaceutical Technologies, (351-368) 2015 Scrivener Publishing LLC 

Further advances in technology offered the solution of surface modification of the metal structure of the DES by chemical or physical adsorption of biopolymers or synthetic polymers that would allow enhanced cell adhesion following placement of the stent. Thus, pharmaceutical polymers may be used not only in the design of the actual stent, but also to coat stent surfaces to augment tissue compatibility. At the present time there are a few DES which are approved by the Food and Drug Authority (FDA) for use in humans. These are further discussed below. 

The second generalization, developed mainly by Koshland, is based on the recognition that enzymes (like any protein) have a multitude of conformations at equilibrium. Since the ligand is likely to interact differently with the various conformations, one can expect a shift in the distribution of conformations induced by the binding process. This is the induced fit model. It states that the best fit (by either geometrical or by a complementary pattern) does not necessarily exist before 

It was pointed out in Section 6.8 that the term allosteric as coined by MCJ and MWC has been used with three different meanings. In Chapter 6 we discussed the allosteric effect in hemoglobin (Hb). There, the two allosteric sites were identical this has been referred to as the homotropic effect. When the two sites bind different ligands, the heterotropic effect, the induced fit by one ligand can either enhance or diminish the binding affinity of the second ligand (see the example in Section 4.5). 

The possibility that the induced fit model might also be used to explain the working mechanism of regulatory enzymes was already mentioned by Koshland himself (1962). 

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Process Analytical Chemistry Introduction and Historical Perspective... 

Webber, E. Vogtle, F. In Introduction and Historical Perspective, Comprehensive Supramolecular Chemistry Vogtle, F. Ed., Pergamon Tarrytown, NY, 1996 Vol. 2, pp 1-28. 

Olajos, E., Stopford, W. (2004). Introduction and historical perspectives. In Riot Control Agents (E. Olajos, W. Stopford, eds), pp. 1-15. Informa Healthcare, New York, NY. 

Olajos, E.J. and Stopford, W., Introduction and historical perspective, in Riot Control Agents Issues in Toxicology, Safety, and Health, Olajos, E.W. and Stopford, W., Eds., CRC Press, Boca Raton, FL, 2004, pp. 1-24. 

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