Cassim J Y, Taylor E W
Biophys J. 1965 Jul;5(4):573-89. doi: 10.1016/S0006-3495(65)86735-2.
The Moffitt b(0) parameter of poly-L-glutamic acid in the presumed helical state varied with solvent composition, ranging in magnitude from less than 600 degrees in aqueous solution to 800 degrees in methanol. b(0) was also dependent on temperature throughout the excessable temperature range. The value in aqueous solution is at least 100 degrees smaller than the values for a number of polypeptides in organic solvents, when compared at the same refractive index. Therefore the optical rotatory dispersion data do not provide evidence that the molecule is completely helical in aqueous solution. Since other types of evidence for helical content are not sufficient to establish that PLGA is a complete helix, the helical content of proteins and polypeptides determined by rotatory dispersion measurements should be regarded as uncertain by about 20 per cent.
处于假定螺旋状态的聚-L-谷氨酸的莫菲特b(0)参数随溶剂组成而变化，其大小范围从水溶液中的小于600度到甲醇中的800度。在整个可测量温度范围内，b(0)也取决于温度。当在相同折射率下比较时，水溶液中的值比许多有机溶剂中的多肽的值至少小100度。因此，旋光色散数据没有提供证据表明该分子在水溶液中是完全螺旋的。由于其他类型的螺旋含量证据不足以确定聚-L-谷氨酸是一个完整的螺旋，通过旋光色散测量确定的蛋白质和多肽的螺旋含量应被视为约20%的不确定性。
