Document Detail


Structure of the pore-helix of the hERG K(+) channel.
MedLine Citation:
PMID:  19305991     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The hERG K(+) channel undergoes rapid inactivation that is mediated by 'collapse' of the selectivity filter, thereby preventing ion conduction. Previous studies have suggested that the pore-helix of hERG may be up to seven residues longer than that predicted by homology with channels with known crystal structures. In the present work, we determined structural features of a peptide from the pore loop region of hERG (residues 600-642) in both sodium dodecyl sulfate (SDS) and dodecyl phosphocholine (DPC) micelles using NMR spectroscopy. A complete structure calculation was done for the peptide in DPC, and the localization of residues inside the micelles were analysed by using a water-soluble paramagnetic reagent with both DPC and SDS micelles. The pore-helix in the hERG peptide was only two-four residues longer at the N-terminus, compared with the pore helices seen in the crystal structures of other K(+) channels, rather than the seven residues suggested from previous NMR studies. The helix in the peptide spanned the same residues in both micellar environments despite a difference in the localization inside the respective micelles. To determine if the extension of the length of the helix was affected by the hydrophobic environment in the two types of micelles, we compared NMR and X-ray crystallography results from a homologous peptide from the voltage gated potassium channel, KcsA.
Authors:
Guilhem Pages; Allan M Torres; Pengchu Ju; Paramjit S Bansal; Paul F Alewood; Philip W Kuchel; Jamie I Vandenberg
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-03-21
Journal Detail:
Title:  European biophysics journal : EBJ     Volume:  39     ISSN:  1432-1017     ISO Abbreviation:  Eur. Biophys. J.     Publication Date:  2009 Dec 
Date Detail:
Created Date:  2009-11-09     Completed Date:  2010-02-01     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8409413     Medline TA:  Eur Biophys J     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  111-20     Citation Subset:  IM    
Affiliation:
School of Molecular and Microbial Biosciences, University of Sydney, Sydney, NSW, 2006, Australia.
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MeSH Terms
Descriptor/Qualifier:
Amino Acid Sequence
Ether-A-Go-Go Potassium Channels / chemistry*
Humans
Hydrophobicity
Micelles
Models, Molecular
Molecular Sequence Data
Nuclear Magnetic Resonance, Biomolecular
Phosphorylcholine / analogs & derivatives,  chemistry
Porosity
Protein Structure, Secondary
Sodium Dodecyl Sulfate / chemistry
Chemical
Reg. No./Substance:
0/Ether-A-Go-Go Potassium Channels; 0/Micelles; 107-73-3/Phosphorylcholine; 151-21-3/Sodium Dodecyl Sulfate; 53949-18-1/dodecylphosphocholine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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