Rotameric preferences of a protein spin label at edge-strand β-sheet sites.

ABSTRACT: Protein spin labeling to yield the nitroxide-based R1 side chain is a powerful method to measure protein dynamics and structure by electron spin resonance. However, R1 measurements are complicated by the flexibility of the side chain. While analysis approaches for solvent-exposed α-helical environment have been developed to partially account for flexibility, similar work in β-sheets is lacking. The goal of this study is to provide the first essential steps for understanding the conformational preferences of R1 within edge β-strands using X-ray crystallography and double electron electron resonance (DEER) distance measurements. Crystal structures yielded seven rotamers for a non-hydrogen-bonded site and three rotamers for a hydrogen-bonded site. The observed rotamers indicate contextual dif

SUBMITTER: Cunningham TF 

PROVIDER: S-EPMC4838652 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature