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Acta Biochim Biophys Sin (Shanghai)
2009 Oct 01;4110:858-64. doi: 10.1093/abbs/gmp077.
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Characterization of a novel alpha4/4-conotoxin, Qc1.2, from vermivorous Conus quercinus.
Peng C
,
Chen W
,
Han Y
,
Sanders T
,
Chew G
,
Liu J
,
Hawrot E
,
Chi C
.
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As part of continuing studies of the identification of gene organization and cloning of novel alpha-conotoxins, the first alpha4/4-conotoxin identified in a vermivorous Conus species, designated Qc1.2, was originally obtained by cDNA and genomic DNA cloning from Conus quercinus collected in the South China Sea. The predicted mature toxin of Qc1.2 contains 14 amino acid residues with two disulfide bonds (I-III, II-IV connectivity) in a native globular configuration. The mature peptide of Qc1.2 is supposed to contain an N-terminal post-translationally processed pyroglutamate residue and a free carboxyl C-terminus. This peptide was chemically synthesized and refolded for further characterization of its functional properties. The synthetic Qc1.2 has two interconvertible conformations in aqueous solution, which may be due to the cis-trans isomerization of the two successive Pro residues in its first Cys loop. Using the Xenopus oocyte heterologous expression system, Qc1.2 was shown to selectively inhibit both rat neuronal alpha3beta2 and alpha3beta4 subtypes of nicotinic acetylcholine receptors with low potency. A block of about 63% and 37% of the ACh-evoked currents was observed, respectively, and the toxin dissociated rapidly from the receptors. Compared with other characterized alpha-conotoxin members, the unusual structural features in Qc1.2 that confer to its receptor recognition profile are addressed.
Azam,
Alpha-conotoxin BuIA, a novel peptide from Conus bullatus, distinguishes among neuronal nicotinic acetylcholine receptors.
2005, Pubmed,
Xenbase
Azam,
Alpha-conotoxin BuIA, a novel peptide from Conus bullatus, distinguishes among neuronal nicotinic acetylcholine receptors.
2005,
Pubmed
,
Xenbase
Chi,
NMR structure determination of alpha-conotoxin BuIA, a novel neuronal nicotinic acetylcholine receptor antagonist with an unusual 4/4 disulfide scaffold.
2006,
Pubmed
Craik,
Chemical modification of conotoxins to improve stability and activity.
2007,
Pubmed
Favreau,
Biochemical characterization and nuclear magnetic resonance structure of novel alpha-conotoxins isolated from the venom of Conus consors.
1999,
Pubmed
Gerzanich,
Homomers of alpha 8 and alpha 7 subunits of nicotinic receptors exhibit similar channel but contrasting binding site properties.
1994,
Pubmed
,
Xenbase
Gray,
Conotoxin MI. Disulfide bonding and conformational states.
1983,
Pubmed
Jones,
Nicotinic receptors in the brain: correlating physiology with function.
1999,
Pubmed
Kang,
Protein folding determinants: structural features determining alternative disulfide pairing in alpha- and chi/lambda-conotoxins.
2007,
Pubmed
Levandoski,
Chimeric analysis of a neuronal nicotinic acetylcholine receptor reveals amino acids conferring sensitivity to alpha-bungarotoxin.
1999,
Pubmed
,
Xenbase
Lindstrom,
Nicotinic acetylcholine receptors in health and disease.
1997,
Pubmed
Liu,
Two potent alpha3/5 conotoxins from piscivorous Conus achatinus.
2007,
Pubmed
,
Xenbase
Lloyd,
Neuronal nicotinic acetylcholine receptors as novel drug targets.
2000,
Pubmed
López-Vera,
A novel alpha conotoxin (alpha-PIB) isolated from C. purpurascens is selective for skeletal muscle nicotinic acetylcholine receptors.
2007,
Pubmed
López-Vera,
Novel alpha-conotoxins from Conus spurius and the alpha-conotoxin EI share high-affinity potentiation and low-affinity inhibition of nicotinic acetylcholine receptors.
2007,
Pubmed
Loughnan,
Physico-chemical characterization and synthesis of neuronally active alpha-conotoxins.
2004,
Pubmed
Martinez,
alpha-Conotoxin EI, a new nicotinic acetylcholine receptor antagonist with novel selectivity.
1995,
Pubmed
Maslennikov,
Two distinct structures of alpha-conotoxin GI in aqueous solution.
1998,
Pubmed
Nicke,
Alpha-conotoxins as tools for the elucidation of structure and function of neuronal nicotinic acetylcholine receptor subtypes.
2004,
Pubmed
Nutt,
Metabolic regulation of oocyte cell death through the CaMKII-mediated phosphorylation of caspase-2.
2005,
Pubmed
,
Xenbase
Peng,
alpha4/7-conotoxin Lp1.1 is a novel antagonist of neuronal nicotinic acetylcholine receptors.
2008,
Pubmed
,
Xenbase
Rosenthal,
The functional role of positively charged amino acid side chains in alpha-bungarotoxin revealed by site-directed mutagenesis of a His-tagged recombinant alpha-bungarotoxin.
1999,
Pubmed
,
Xenbase
Sanders,
A novel pharmatope tag inserted into the beta4 subunit confers allosteric modulation to neuronal nicotinic receptors.
2004,
Pubmed
,
Xenbase
Shon,
mu-Conotoxin PIIIA, a new peptide for discriminating among tetrodotoxin-sensitive Na channel subtypes.
1998,
Pubmed
Wang,
A novel short-chain peptide BmKX from the Chinese scorpion Buthus martensi Karsch, sequencing, gene cloning and structure determination.
2005,
Pubmed
Yuan,
From the identification of gene organization of alpha conotoxins to the cloning of novel toxins.
2007,
Pubmed
