Fast helix formation in the B domain of protein A revealed by site-specific infrared probes.

ABSTRACT: Comparison of experimental and computational protein folding studies can be difficult because of differences in structural resolution. Isotope-edited infrared spectroscopy offers a direct measure of structural changes involved in protein folding at the single-residue level. Here we demonstrate the increased resolution of site-specific infrared probes to the peptide backbone in the B domain of staphylococcal protein A (BdpA). (13)C═(18)O-labeled methionine was incorporated into each of the helices using recombinant protein expression. Laser-induced temperature jumps coupled with infrared spectroscopy were used to probe changes in the peptide backbone on the submillisecond time scale. The relaxation kinetics of the buried helices, solvated helices, and labeled positions were measured indepen

SUBMITTER: Davis CM 

PROVIDER: S-EPMC4356530 | biostudies-literature | 2015 Mar

REPOSITORIES: biostudies-literature