jp304240e_si_001.pdf (3.12 MB)
Spectral Marker for Cα Damage in Beta Peptides
journal contribution
posted on 2013-01-24, 00:00 authored by Mandy
C. Green, Sarah Stelzleni, Joseph S. FranciscoThe work in this article describes a spectral signature
for the
detection of a Cα radical damaged peptide, which
should enable the use of infrared spectroscopic methods to directly
monitor oxidative events. Spectra for radical damaged peptides are
computed with ab initio methods. The amide bands A, I, II, and III
are analyzed for trends in the damage site. The spectral signature
is found in a region (i.e., 1700–1620 cm–1) normally void of vibrational absorption bands from stable undamaged
beta peptides. An analysis of the vibrational motions of the spectral
signature is described. The uniqueness of the spectral signature is
explored by an examination and comparison with Cα monoradicals and polyradicals, as well as with other bioradicals
that could act as spectral interferences. The identification of unique
infrared spectral features for Cα damage could have
important implications in diagnostics for beta conformational peptides
damaged by oxidative stress processes.