2gcz
From Proteopedia
Solution Structure of alpha-Conotoxin OmIA
Structural highlights
FunctionCA1A_CONOM Alpha-conotoxins act on postsynaptic membranes, they bind to the nicotinic acetylcholine receptors (nAChR) and thus inhibit them. This toxin blocks alpha-3/beta-2 (IC(50)=11 nM), alpha-7 (IC(50)=27.1) and alpha-6/alpha-3-beta-2-beta-3 (IC(50)=201 nM) subunits of nAChR.[1] Publication Abstract from PubMedalpha-Conotoxin OmIA from Conus omaria is the only alpha-conotoxin that shows a approximately 20-fold higher affinity to the alpha3beta2 over the alpha6beta2 subtype of nicotinic acetylcholine receptor. We have determined a three-dimensional structure of alpha-conotoxin OmIA by nuclear magnetic resonance spectroscopy. alpha-Conotoxin OmIA has an "omega-shaped" overall topology with His(5)-Asn(12) forming an alpha-helix. Structural features of alpha-conotoxin OmIA responsible for its selectivity are suggested by comparing its surface characteristics with other functionally related alpha4/7 subfamily conotoxins. Reduced size of the hydrophilic area in alpha-conotoxin OmIA seems to be associated with the reduced affinity towards the alpha6beta2 nAChR subtype. Solution conformation of a neuronal nicotinic acetylcholine receptor antagonist alpha-conotoxin OmIA that discriminates alpha3 vs. alpha6 nAChR subtypes.,Chi SW, Kim DH, Olivera BM, McIntosh JM, Han KH Biochem Biophys Res Commun. 2006 Jun 23;345(1):248-54. Epub 2006 Apr 27. PMID:16678128[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
|
Categories: Conus omaria | Large Structures | Chi S-W | Han K-H | Kim D-H | McIntosh JM | Olivera BM