Peptide C(alpha)D(alpha) stretch frequencies in a hydrated conformation are perturbed mainly by C(alpha)-D(alpha)...O hydrogen bonding.
We have shown (J. Phys. Chem. A 2004, 108, 10923; 2007, 111, 5300) that the C(alpha)D(alpha) stretch frequency, nu(CD), can discriminate between uniform alpha(R), beta, and polyproline II conformations of isolated peptides. Similar results for such peptides to which explicit waters are hydrogen bonded exhibit shifts in nu(CD) from those of the isolated structures. We demonstrate that the main source of these frequency shifts is the formation of C(alpha)-D(alpha)...O hydrogen bonds to water. Taking into account C-H...O(water) hydrogen bonding, together with the traditional bonding of peptide groups to water, can be expected to increase our understanding of the interaction of proteins with their aqueous environment.
Mirkin
Noemi G
NG
LSA Biophysics, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109-1055, USA.
Krimm
Samuel
S
D000244:Adenosine Diphosphate / Q000737:chemistry; D006860:Hydrogen Bonding; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D013057:Spectrum Analysis; D014867:Water / Q000737:chemistry
D010455:Peptides; D014867:Water; D000244:Adenosine Diphosphate