Maxfield F R, Scheraga H A
Biochemistry. 1977 Oct 4;16(20):4443-9. doi: 10.1021/bi00639a018.
The conformation of the CCSSCC moiety in oxytocin and lysine vasopressin is investigated using laser Raman spectroscopy. The Raman spectra of solutions of these hormones in water and in dimethyl sulfoxide show an intense band at 508 cm-1 which is assigned to the S-S stretching mode. The presence of shoulders on this band between 490 and 525 cm-1 shows that there is an equilibrium among several conformations for the disulfide unit of these hormones in solution. Most of the CS-SC dihedral angles are within 30 degrees of +/-90 degrees, but some of the molecules have CS-SC dihedral angles strained away from this value by more than 30 degrees. The previously published circular dichroism spectra of these hormones are reinterpreted, and it is shown that the circular dichroism spectra indicate the presence of more than one conformation for the disulfide unit, in agreement with the Raman results.
利用激光拉曼光谱研究了催产素和赖氨酸加压素中CCSSCC部分的构象。这些激素在水和二甲基亚砜中的溶液的拉曼光谱在508 cm-1处显示出一条强带，该带被指定为S-S伸缩模式。在490至525 cm-1之间该带出现的肩峰表明，这些激素溶液中，其二硫键单元的几种构象之间存在平衡。大多数CS-SC二面角在+/-90度的30度范围内，但一些分子的CS-SC二面角偏离该值超过30度。对这些激素先前发表的圆二色光谱进行了重新解释，结果表明，圆二色光谱表明二硫键单元存在不止一种构象，这与拉曼结果一致。
