Coil-Helix Transition in Polypeptides

Principles of Polymer Chemistry, Cornell Univ. ftess, Ithaca, NY (1953). 

Dunlop, K. R. Harris, and D. J. Young, Experimental Methods for Studying Diffusion in Gases, Liquids, and Sohds, in B. W. Rossiter and R. C. Baetzold (eds.). Physical Methods of Chemistry, 2d ed., vol. VI, chap. 3, Wiley-Interscience, New York (1992). 

Einstein, Investigations on the Theory of Brownian Movement, chap. IB, Dover, New York (1956) R. J. Silbey, R. A. Alberty, and M. G. Bawendi, Physical Chemistry, 4th ed., p. 776, Wiley, New York (2005). 

Organic Chemistry of Synthetic High Polymers, pp. 26I-27I, 305-369, Wiley-Interscience, New York (1967). 

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Lifson, S. Roig, A., Theory of helix-coil transition in polypeptides, J. Chem. Phys. 1961, 34, 1963-1974. 

Typical examples are the conversion of the neutral form of an amino acid into its zwitterionic form, the helix-coil transitions in polypeptides and polynucleotides, and other conformational changes in biopolymers. Reactions of higher molecularity in which reactants and products have different dipole moments are subject to the same effect (association of the carboxylic acids to form hydrogen-bonded dimers). Equilibrium involving ions are often more sensitive to the application of an electric field ... 

According to this model, the observed sharpness of the helix-coil transition in polypeptide chains is due to the following circumstance the formation of the first turn of the helix is difficult because of the large reduction of entropy, but, once formed, the first turn acts as a nucleus to stabilize the formation of further turns by hydrogen bonding. 

Lifson S, Roig A (1961) On the theory of helix-coil transitions in polypeptides. J Chem Phys 34 1963-1974... 

It is worth mentioning that the helix-coil model without long-range interactions found applications far beyond the area of DNA biophysics. Among other applications, the model has been extensively used to study of helix-coil transition in polypeptides and most recently it was used by Selinger and Selinger (1996) [64] to explain experimental data on chiral order in random copolymers consisting of two enantiomers. 

Takashi Norisuye received his PhD degree in polymer science from Osaka University, Osaka, japan, in 1973. Two years earlier than this, he actually started his tenure work on polymer science as Assistant Professor at the Department of Polymer Science (currently, the Department of Maaomolecular Science), Osaka University. He was promote to associate professor and professor ofthe same department in 1986 and 1996, respectively, and retired in 2007. He is now Emeritus Professor of Osaka Univeisity. Throughout his scientific carrier, he worked on solution properties of macromol niles both theoretically and experimentally with particular interest in excluded-volume effects, helix-coil transition in polypeptides, stiff or rigid chains, polysaccharides, and polyelectrolytes. For those experimental studies, he used sudi t diniques as light and SAlffi, ultracentrifugation, osmometry, polarimetry, NMR, and viscometry. 

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