Theoretical π-π* circular dichroic spectra of helical poly(glycine) and poly(L-alanine) as functions of backbone torsion angles

✍ Scribed by Jon Applequist

• Publisher: Wiley (John Wiley & Sons)
• Year: 1981
• Tongue: English
• Weight: 633 KB
• Volume: 20
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1981.360200210

✦ Synopsis

Abstract

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.