Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10564652 | Vibrational Spectroscopy | 2011 | 9 Pages |
Abstract
In this work we analyzed the specificity of the amide VI band for different types of secondary structure elements in protein structures. This band involves the bending motion of the CO group of the peptide chain that is typically observed in the spectral region from 590 to 490 cmâ1. The infrared absorbance spectra of a set of polypeptide model compounds of well known secondary structure was obtained at defined pH, including poly (l-lysine), poly (l-tyrosine), poly (l-alanine) and poly (l-histidine). In addition spectra of membrane proteins from the respiratory chain, namely the NADH:ubiquinone oxidoreductase, the cytochrome c oxidase and its CuA fragment, the cytochrome bc1 complex, a Rieske-type protein and in addition myoglobin, have been comparatively investigated. The systematic analysis of the amide VI band of the polypeptides and the proteins allowed correlating the signal appearing at â¼525 cmâ1 to α-helical structures and signals at â¼545 cmâ1 to β-sheet contributions. Random coils have been found to contribute at â¼535 cmâ1 while the β-turns were observed at â¼560 cmâ1.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Youssef El Khoury, Ruth Hielscher, Mariana Voicescu, Julien Gross, Petra Hellwig,