Premium
Theoretical π‐π* circular dichroic spectra of helical poly(glycine) and poly( L ‐alanine) as functions of backbone torsion angles
Author(s) -
Applequist Jon
Publication year - 1981
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1981.360200210
Subject(s) - dichroic glass , torsion (gastropod) , chemistry , helix (gastropod) , dipole , spectral line , dihedral angle , crystallography , alanine , molecular physics , physics , optics , molecule , amino acid , hydrogen bond , quantum mechanics , anatomy , medicine , ecology , biochemistry , organic chemistry , biology , snail
Circular dichroic spectra and oscillator strengths of the π‐π transition near 190 nm are calculated for helical (Gly) 6 and (Ala) 6 at 30° intervals of the backbone torsion angles (ϕ,ψ) over the range ‐180° ≤ ϕ ≤ ‐60°, −60° ≤ ψ ≤ 180°, using the partially dispersive normal mode treatment of the dipole interaction model. Polarizabilities of atoms and the NC′O group are those determined semiempirically in previous studies. Calculations for (Ala) 6 at (ϕ,ψ) angles corresponding to the α‐helix, the poly(Pro) II helix, a collagen single helix, a poly‐(MeAla) helix, and single β‐helices are found to agree well with most of the available experimental data.