UV raman examination of alpha-helical peptide water hydrogen bonding

J Am Chem Soc. 2005 Mar 9;127(9):2840-1. doi: 10.1021/ja044708f.

Abstract

UV resonance Raman spectra (UVRS) of an alpha-helical, 21 residue, mainly Ala peptide (AP) in the dehydrated solid state were compared to those in aqueous solution at different temperatures. The UVRS amide band frequencies of a dehydrated solid alpha-helix peptide show frequency shifts compared to those in aqueous solution due to the loss of amide backbone hydrogen bonding to water; the amide II and amide III bands of the solid alpha-helix downshift, while the amide I band upshifts. The shifts are identical in direction but smaller than those that occur for alpha-helices in aqueous solution as the temperature increases; water hydrogen bonding strengths decrease as the temperature increases. The UV Raman amide band frequency shifts can be used to monitor alpha-helix hydrogen bonding.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cold Temperature
  • Hot Temperature
  • Hydrogen Bonding
  • Kinetics
  • Peptides / chemistry*
  • Polyglutamic Acid / chemistry
  • Polylysine / chemistry
  • Protein Structure, Secondary
  • Spectrophotometry, Ultraviolet / methods
  • Spectrum Analysis, Raman / methods
  • Water / chemistry*

Substances

  • Peptides
  • Water
  • Polylysine
  • polyalanine
  • Polyglutamic Acid