Cesàro A, Paoletti S, Guidugli S, Benegas J C
Dipartimento di Biochimica, Biofisica e Chimica delle Macromolecole, Università di Trieste, 34127 Trieste, Italy.
Biophys Chem. 1991 Jan;39(1):9-16. doi: 10.1016/0301-4622(91)85002-8.
The cooperative conformational transition of poly(L-glutamic acid) induced by pH is monitored by the titration curves from literature. The polyelectrolytic approach described in the preceding article (A. Cesàro, S. Paoletti and J.C. Benegas, Biophys. Chem. 39 (1991) 1) is used to fit the experimental curves under various conditions of ionic strength and temperature, with the sole assumption that each polymeric state is characterized by a proper conformational flexibility. The helix-coil transition of the system becomes molecularly defined by the balance between the non-ionic conformational energy and the repulsive electrostatic energy of the two forms. Implications of the results of the theoretical model on the energetics of the cooperative order-disorder transition are discussed.
由pH值诱导的聚（L-谷氨酸）的协同构象转变通过文献中的滴定曲线进行监测。前文（A. 切萨罗、S. 保莱蒂和J.C. 贝内加斯，《生物物理化学》39 (1991) 1）中描述的聚电解质方法用于拟合在不同离子强度和温度条件下的实验曲线，唯一的假设是每种聚合物状态都具有适当的构象灵活性。该系统的螺旋-卷曲转变通过两种形式的非离子构象能与排斥静电能之间的平衡在分子层面上得以确定。讨论了理论模型结果对协同有序-无序转变能量学的影响。
