Osmolyte perturbation reveals conformational equilibria in spin-labeled proteins.

ABSTRACT: Recent evidence suggests that proteins at equilibrium can exist in a manifold of conformational substates, and that these substates play important roles in protein function. Therefore, there is great interest in identifying regions in proteins that are in conformational exchange. Electron paramagnetic resonance spectra of spin-labeled proteins containing the nitroxide side chain (R1) often consist of two (or more) components that may arise from slow exchange between conformational substates (lifetimes > 100 ns). However, crystal structures of proteins containing R1 have shown that multicomponent spectra can also arise from equilibria between rotamers of the side chain itself. In this report, it is shown that these scenarios can be distinguished by the response of the system to solvent pert

SUBMITTER: Lopez CJ 

PROVIDER: S-EPMC2776952 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature