| Literature DB >> 15833744 |
Monika Bayrhuber1, Vinesh Vijayan, Michael Ferber, Roland Graf, Jegannath Korukottu, Julita Imperial, James E Garrett, Baldomero M Olivera, Heinrich Terlau, Markus Zweckstetter, Stefan Becker.
Abstract
Conkunitzin-S1 (Conk-S1) is a 60-residue neurotoxin from the venom of the cone snail Conus striatus that interacts with voltage-gated potassium channels. Conk-S1 shares sequence homology with Kunitz-type proteins but contains only two out of the three highly conserved cysteine bridges, which are typically found in these small, basic protein modules. In this study the three-dimensional structure of Conk-S1 has been solved by multidimensional NMR spectroscopy. The solution structure of recombinant Conk-S1 shows that a Kunitz fold is present, even though one of the highly conserved disulfide cross-links is missing. Introduction of a third, homologous disulfide bond into Conk-S1 results in a functional toxin with similar affinity for Shaker potassium channels. The affinity of Conk-S1 can be enhanced by a pore mutation within the Shaker channel pore indicating an interaction of Conk-S1 with the vestibule of potassium channels.Entities:
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Year: 2005 PMID： 15833744 DOI： 10.1074/jbc.C500064200
Source DB: PubMed Journal: J Biol Chem ISSN： 0021-9258 Impact factor: 5.157