Vibrational studies of the disulfide group in proteins : Part III. A simplified ab initio force field for diethyl disulfide and SS and CS stretch frequency--conformation correlations for diisobutyl disulfide

Abstract

We have obtained a simplified ab initio force field for diethyl disulfide, based on our previous scaled ab initio force field, which can be used in normal coordinate analysis of proteins containing the disulfide bridge. A normal coordinate analysis has been performed for diisobutyl disulfide in all possible conformations. The correlations thus obtained between the SS and CS stretch frequencies and the conformation are useful in understanding similar correlations in proteins containing the disulfide bridge. A simple way is presented to identify local C2 symmetry in a disulfide bridge through Raman polarization studies.