Bacteriorhodopsin Folds through a Poorly Organized Transition State

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• 作者：Jonathan P. Schlebach ; Nicholas B. Woodall ; James U. Bowie ; Chiwook Park
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：November 26, 2014
• 年：2014
• 卷：136
• 期：47
• 页码：16574-16581
• 全文大小：412K
• ISSN：1520-5126

文摘

The folding mechanisms of helical membrane proteins remain largely uncharted. Here we characterize the kinetics of bacteriorhodopsin folding and employ 蠁-value analysis to explore the folding transition state. First, we developed and confirmed a kinetic model that allowed us to assess the rate of folding from SDS-denatured bacteriorhodopsin (bR_U) and provides accurate thermodynamic information even under influence of retinal hydrolysis. Next, we obtained reliable 蠁-values for 16 mutants of bacteriorhodopsin with good coverage across the protein. Every 蠁-value was less than 0.4, indicating the transition state is not uniquely structured. We suggest that the transition state is a loosely organized ensemble of conformations.