Characterization of the gating brake in the I-II loop of Ca(v)3.2 T-type Ca(2+) channels.

ABSTRACT: Mutations in the I-II loop of Ca(v)3.2 channels were discovered in patients with childhood absence epilepsy. All of these mutations increased the surface expression of the channel, whereas some mutations, and in particular C456S, altered the biophysical properties of channels. Deletions around C456S were found to produce channels that opened at even more negative potentials than control, suggesting the presence of a gating brake that normally prevents channel opening. The goal of the present study was to identify the minimal sequence of this brake and to provide insights into its structure. A peptide fragment of the I-II loop was purified from bacteria, and its structure was analyzed by circular dichroism. These results indicated that the peptide had a high alpha-helical content, as predic

SUBMITTER: Arias-Olguin II 

PROVIDER: S-EPMC2276388 | biostudies-literature | 2008 Mar

REPOSITORIES: biostudies-literature