Helix formation via conformation diffusion search.
The helix-coil transition kinetics of an alpha-helical peptide were investigated by time-resolved infrared spectroscopy coupled with laser-induced temperature-jump initiation method. Specific isotope labeling of the amide carbonyl groups with 13C at selected residues was used to obtain site-specific information. The relaxation kinetics following a temperature jump, obtained by probing the amide I' band of the peptide backbone, exhibit nonexponential behavior and are sensitive to both initial and final temperatures. These data are consistent with a conformation diffusion process on the folding energy landscape, in accord with a recent molecular dynamics simulation study.
Huang
Cheng-Yen
CY
Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA.
Getahun
Zelleka
Z
Zhu
Yongjin
Y
Klemke
Jason W
JW
DeGrado
William F
WF
Gai
Feng
F
D003198:Computer Simulation; D004058:Diffusion; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared
D010455:Peptides