Populations of the three major backbone conformations in 19 amino acid dipeptides.

ABSTRACT: The amide III region of the peptide infrared and Raman spectra has been used to determine the relative populations of the three major backbone conformations (P(II), β, and α(R)) in 19 amino acid dipeptides. The results provide a benchmark for force field or other methods of predicting backbone conformations in flexible peptides. There are three resolvable backbone bands in the amide III region. The major population is either P(II) or β for all dipeptides except Gly, whereas the α(R) population is measurable but always minor (≤ 10%) for 18 dipeptides. (The Gly ϕ,ψ map is complex and so is the interpretation of the amide III bands of Gly.) There are substantial differences in the relative β and P(II) populations among the 19 dipeptides. The band frequencies have been assigned as P(II), 1,317

SUBMITTER: Grdadolnik J 

PROVIDER: S-EPMC3033284 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature