The role of extramembranous cytoplasmic termini in assembly and stability of the tetrameric K(+)-channel KcsA.

ABSTRACT: Membrane-active alcohol 2,2,2-trifluoroethanol has been proven to be an attractive tool in the investigation of the intrinsic stability of integral membrane protein complexes by taking K(+)-channel KcsA as a suitable and representative ion channel. In the present study, the roles of both cytoplasmic N and C termini in channel assembly and stability of KcsA were determined. The N terminus (1-18 residues) slightly increased tetramer stability via electrostatic interactions in the presence of 30 mol.% acidic phosphatidylglycerol (PG) in phosphatidylcholine lipid bilayer. Furthermore, the N terminus was found to be potentially required for efficient channel (re)assembly. In contrast, truncation of the C terminus (125-160 residues) greatly facilitated channel reversibility from either a partial

SUBMITTER: Raja M 

PROVIDER: S-EPMC2864438 | biostudies-literature | 2010 May

REPOSITORIES: biostudies-literature