title: Helix formation via conformation diffusion search.
abstract: 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.
authors.affiliation: Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: Cheng-Yen
authors.initials: CY
authors.lastname: Huang
authors.forename: Zelleka
authors.initials: Z
authors.lastname: Getahun
authors.forename: Yongjin
authors.initials: Y
authors.lastname: Zhu
authors.forename: Jason W
authors.initials: JW
authors.lastname: Klemke
authors.forename: William F
authors.initials: WF
authors.lastname: DeGrado
authors.forename: Feng
authors.initials: F
authors.lastname: Gai
mesh_terms: D003198:Computer Simulation; D004058:Diffusion; D008958:Models, Molecular; D010455:Peptides / Q000737:chemistry*; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D010455:Peptides