Isolation and characterization of ¦Á-conotoxin LsIA with potent activity at nicotinic acetylcholine receptors
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- 作者：Marco C. Inserra ; Shiva N. Kompella ; Irina Vetter ; Andreas Brust ; Norelle L. Daly ; Hartmut Cuny ; David J. Craik ; Paul F. Alewood ; David J. Adams ; Richard J. Lewis
- 关键词：nAChR ; nicotinic acetylcholine receptor ; RP-HPLC ; reverse phase-high performance liquid chromatography ; NMR ; nuclear magnetic resonance ; ACh ; acetylcholine ; GPCR ; G protein-coupled receptor ; FLIPR ; fluorometric imaging plate reader ; IC50 ; half-maximal inh
- 刊名：Biochemical Pharmacology
- 出版年：2013
- 出版时间：15 September, 2013
- 年：2013
- 卷：86
- 期：6
- 页码：791-799
- 全文大小：1294 K
文摘
A new ¦Á-conotoxin LsIA was isolated from the crude venom of Conus limpusi using assay-guided RP-HPLC fractionation. Synthetic LsIA was a potent antagonist of ¦Á3¦Â2, ¦Á3¦Á5¦Â2 and ¦Á7 nAChRs, with half-maximal inhibitory concentrations of 10, 31 and 10 nM, respectively. The structure of LsIA determined by NMR spectroscopy comprised a characteristic disulfide bond-stabilized ¦Á-helical structure and disordered N-terminal region. Potency reductions of up to 9-fold were observed for N-terminally truncated analogues of LsIA at ¦Á7 and ¦Á3¦Â2 nAChRs, whereas C-terminal carboxylation enhanced potency 3-fold at ¦Á3¦Â2 nAChRs but reduced potency 3-fold at ¦Á7 nAChRs. This study gives further insight into ¦Á-conotoxin pharmacology and the molecular basis of nAChR selectivity, highlighting the influence of N-terminal residues and C-terminal amidation on conotoxin pharmacology.