Abstract
The conformational transition (random coil–α helix–β form) of a sodium poly(L-glutamate) has been examined in solution at various concentrations and temperatures by infrared absorption spectra, X-ray diffraction, differential scanning calorimetry, and polarized microscopy. At room temperature, random coil conformation is retained at a dilute concentration below 40%, and the a helix is formed within a concentration range from 45—70%, and at a concentration above 75%, the β form is a stable conformation. Either the thermal transition of the a helix-random coil or the a helix-β form is accompanied with the endothermic peak in a thermogram depending on the solution concentration. Also, within a concentration range from 45—70%, the concentrated solution forms the anisotropic phase which consists the α helix, i.e., the lyotropic cholesteric liquid crystal. The anisotropic phase transforms into the isotropic phase with increase in temperature. Spherulites consisting of the β form conformation and which include water between the sheets of the β form could be observed at a concentration above 75%.
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Tsujita, Y., Yamanaka, I. & Takizawa, A. The Conformational Transition in the Concentrated Solution of Sodium Poly(L-GLUTAMATE). Polym J 11, 749–754 (1979). https://doi.org/10.1295/polymj.11.749
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DOI: https://doi.org/10.1295/polymj.11.749
