Fast-time scale dynamics of outer membrane protein A by extended model-free analysis of NMR relaxation data.

ABSTRACT: In order to better understand the dynamics of an integral membrane protein, backbone amide (15)N NMR dynamics measurements of the beta-barrel membrane protein OmpA have been performed at three magnetic fields. A total of nine relaxation data sets were globally analyzed using an extended model-free formalism. The diffusion tensor was found to be prolate axially symmetric with an axial ratio of 5.75, indicating a possible rotation of the protein within the micelle. The generalized order parameters gradually decreased from the mid-plane towards the two ends of the barrel, counteracting the dynamic gradient of the lipids in a matching bilayer, and were dramatically reduced in the extracellular loops. Large-scale internal motions on the ns time scale indicate that entire loops most likely under

SUBMITTER: Liang B 

PROVIDER: S-EPMC2812607 | biostudies-literature | 2010 Feb

REPOSITORIES: biostudies-literature