Vibrational spectroscopy of L -valyl-glycyl-glycine, a parallel-chain Β-structure This is paper number 38 in a series on “Vibrational Analysis of Peptides, Polypeptides, and Proteins,” of which paper number 37 is Ref. 27.

Bands in the ir and Raman spectra of L -valyl-glycyl-glycine (VGG) and VGG-ND have been assigned on the basis of a normal mode analysis of the known parallel-chain Β-structure of this tripeptide. Amide I, II, III, and V mode shifts are obtained by the interactions of dipole derivatives in symmetry coordinates, referred to as dipole derivative coupling. These derivatives, obtained from ab initio studies, are also used to calculate ir intensities of amide I, II, and V modes. The agreement between predicted and observed frequencies and intensities is very good, providing confidence in the application of our force fields to the calculation of the vibrational modes of the general parallel-chain Β-sheet structure (following paper).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37854/1/360270602_ftp.pd

Vibrational analysis of glutathione

Infrared and Raman spectra have been obtained of crystalline glutathione and its deuterated derivative and interpreted by normal mode analysis. The force field consisted of our empirical force fields for the peptide group and NH 3 +3 and CO 2 − end groups, plus our ab initio force fields for the CH 2 SH and CH 2 COOH moieties. Observed bands are reproduced with an average error of 5 cm −1 , demonstrating that the vibrational spectrum of such a complex molecule can be understood in great depth. © 1994 John Wiley & Sons, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37866/1/360341009_ftp.pd