The aim of this paper is to outline new possibilities of more detailed thermodynamic analysis of helix-coil transition parameters, particularly with respect to their splitting into energy and entropy terms. Because of difticulties with the ternary systems, water--organic solvent-polypeptide, or, two organic solventspolypeptide, caused particularly by the phenomenon of specific sorption of one solvent component, the discussion is restricted to water soluble synthetic polypeptides whose limited range can fairly be extended by copolymerization. lt is shown how the combination of data from dillerent experimental sources (optical rotatory dispersion, potentiometric titration curves, intrinsic viscosity. calorimetry) can yield an average number of monomer units in the helical region in the middle of the transition. The parameters characterizing the initiation and elongation ofhelical regions determined for a number of polypeptides dillering only in their side groups give us valuable information about the intramolecular interactions in polypeptide chains. There is also a significant correspondence between the helix coil equilibrium constants of natural amino-acids in aqueous media and the distribution of these amino-acids among helical and non-helical regions in globular proteins. This correspondence, tagether with a treatment of intramolecular interactions, can serve to predict the secondary structure of globular proteins from the primary one.

中文翻译：

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多肽链中螺旋-螺旋转变的热力学参数

本文的目的是概述对螺旋线圈转变参数进行更详细的热力学分析的新可能性，特别是在将它们分解为能量和熵项方面。由于三元体系、水-有机溶剂-多肽或两种有机溶剂多肽的困难，特别是由于一种溶剂组分的特异吸附现象引起的，讨论仅限于水溶性合成多肽，其范围有限。通过共聚作用延长。它显示了来自不同实验来源（旋光色散、电位滴定曲线、特性粘度、量热法）的数据组合如何能够在转变中间的螺旋区域产生平均数量的单体单元。为许多仅在其侧基中分离的多肽确定的表征螺旋区域的起始和延伸的参数为我们提供了有关多肽链中分子内相互作用的宝贵信息。水性介质中天然氨基酸的螺旋线圈平衡常数与这些氨基酸在球状蛋白质中螺旋和非螺旋区域的分布之间也存在显着的对应关系。这种对应与分子内相互作用的处理相结合，可以用于从一级结构预测球状蛋白质的二级结构。水性介质中天然氨基酸的螺旋线圈平衡常数与这些氨基酸在球状蛋白质中螺旋和非螺旋区域的分布之间也存在显着的对应关系。这种对应与分子内相互作用的处理相结合，可以用于从一级结构预测球状蛋白质的二级结构。水性介质中天然氨基酸的螺旋线圈平衡常数与这些氨基酸在球状蛋白质中螺旋和非螺旋区域的分布之间也存在显着的对应关系。这种对应与分子内相互作用的处理相结合，可以用于从一级结构预测球状蛋白质的二级结构。