Point mutations in membrane proteins reshape energy landscape and populate different unfolding pathways.

ABSTRACT: Using single-molecule force spectroscopy, we investigated the effect of single point mutations on the energy landscape and unfolding pathways of the transmembrane protein bacteriorhodopsin. We show that the unfolding energy barriers in the energy landscape of the membrane protein followed a simple two-state behavior and represent a manifestation of many converging unfolding pathways. Although the unfolding pathways of wild-type and mutant bacteriorhodopsin did not change, indicating the presence of same ensemble of structural unfolding intermediates, the free energies of the rate-limiting transition states of the bacteriorhodopsin mutants decreased as the distance of those transition states to the folded intermediate states decreased. Thus, all mutants exhibited Hammond behavior and a chan

SUBMITTER: Sapra KT 

PROVIDER: S-EPMC2742699 | biostudies-literature | 2008 Feb

REPOSITORIES: biostudies-literature