Mapping Membrane Protein Backbone Dynamics: A Comparison of Site-Directed Spin Labeling with NMR N-15-Relaxation Measurements

作者：Lo Ryan H; Kroncke Brett M; Solomon Tsega L; Columbus Linda^*

来源：Biophysical Journal, 2014, 107(7): 1697-1702.

DOI：10.1016/j.bpj.2014.08.018

The ability to detect nanosecond backbone dynamics with site-directed spin labeling (SDSL) in soluble proteins has been well established. However, for membrane proteins, the nitroxide appears to have more interactions with the protein surface, potentially hindering the sensitivity to backbone motions. To determine whether membrane protein backbone dynamics could be mapped with SDSL, a nitroxide was introduced at 55 independent sites in a model polytopic membrane protein, TM0026. Electron paramagnetic resonance spectral parameters were compared with NMR N-15-relaxatioh data. Sequential scans revealed backbone dynamics with the same trends observed for the R-1 relaxation rate, suggesting that nitroxide dynamics remain coupled to the backbone on membrane proteins.

• 出版日期2014-10-7