A novel α4/7-conotoxin LvIA from Conus lividus that selectively blocks α3β2 vs. α6/α3β2β3 nicotinic acetylcholine receptors
A novel α4/7-conotoxin LvIA from Conus lividus that selectively blocks α3β2 vs. α6/α3β2β3 nicotinic acetylcholine receptors
复制标题
一种来自青斑芋螺的新型 α4/7-芋螺毒素 LvIA，选择性阻断 α3β2 与 α6/α3β2β3 烟碱乙酰胆碱受体
DOI：
10.1096/fj.13-244103
复制
发表时间：
2014-04-01
期刊：
影响因子：
4.8
通讯作者：
Whiteaker, Paul
中科院分区：
文献类型：
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作者：
Luo, Sulan;Zhangsun, Dongting;Whiteaker, Paul
本研究旨在发现并表征首个有效的α 3 β 2亚型选择性烟碱乙酰胆碱受体（nAChR）配体。从褐松果中克隆了一种新的α 4/7-松果毒素α - ctxlvia。采用2电极电压钳电生理学方法测定其在非洲爪蟾卵母细胞表达的大鼠nAChR亚型中的药理谱，采用核磁共振波谱法测定其三维结构。α - ctx LvIA是一种16-aa c端修饰的2-二硫桥肽。利用爪蟾卵母细胞中表达的大鼠亚基，我们发现α - ctxlvia对α 3 β 2 nAChRs的亲和力最高（IC50为8.7 nM），阻断在2分钟内可逆。在α 6/ α 3 β 2 β 3、α 6/ α 3 β 4和α 3 β 4 nachr下，IC50值为>= 100 nM，在所有其他测试亚型中，>= 3 μ M。α 3 β 2与α 6 β 2亚型选择性被证实为人类亚基nachr， α 3 β 2比α 6 β 2 nachr具有更大的偏好（300倍）。这是首次报道的对人类α 3 β 2和α 6 β 2 nachr具有高选择性的α - ctx。α - ctxlvia采用两种类似的填充构象水：一个（假定是生物活性的）是高度结构化的，而另一个在本质上大多是随机线圈。与同样有效但选择性较低的α 3 β 2 nAChR拮抗剂α - ctx PeIA的选择性差异可能存在于三个残基中，它们在环2中不同，因为它们在其他方面具有相似的3D结构。α 4/7-CTx LvIA是一种新的、有效的、选择性的α 3 β 2 nAChR拮抗剂，它将使对α 3 β 2 nAChR结构、功能和生理作用的详细研究成为可能。-Luo， S., Zhangsun， D., Schroeder， C. I., Zhu， X., Hu， Y., Wu， Y., Weltzin， M. M., Eberhard， S., Kaas， Q., Craik， D. J., McIntosh， J. M., Whiteaker， P.一种可选择性阻断α 3 β 2和α 6/ α 3 β 2 β 3烟碱乙酰胆碱受体的新型α 4/7- conconus lividus的LvIA。
This study was performed to discover and characterize the first potent alpha 3 beta 2-subtype-selective nicotinic acetylcholine receptor (nAChR) ligand. A novel alpha 4/7-conotoxin, alpha-CTxLvIA, was cloned from Conus lividus. Its pharmacological profile at Xenopus laevis oocyte-expressed rat nAChR subtypes was determined by 2-electrode voltage-clamp electrophysiology, and its 3-dimensional (3D) structure was determined by NMR spectroscopy. alpha-CTx LvIA is a 16-aa C-terminally-amidated peptide with 2-disulfide bridges. Using rat subunits expressed in Xenopus oocytes, we found the highest affinity of alpha-CTxLvIA was for alpha 3 beta 2 nAChRs (IC50 8.7 nM), where blockade was reversible within 2 min. IC50 values were > 100 nM at alpha 6/alpha 3 beta 2 beta 3, alpha 6/alpha 3 beta 4, and alpha 3 beta 4 nAChRs, and >= 3 mu M at all other subtypes tested. alpha 3 beta 2 vs. alpha 6 beta 2 subtype selectivity was confirmed for human-subunit nAChRs with much greater preference (300-fold) for alpha 3 beta 2 over alpha 6 beta 2 nAChRs. This is the first alpha-CTx reported to show high selectivity for human alpha 3 beta 2 vs. alpha 6 beta 2 nAChRs. alpha-CTxLvIA adopts two similarly populated conformations water: one (assumed to be bioactive) is highly structured, whereas the other is mostly random coil in nature. Selectivity differences with the similarly potent, but less selective, alpha 3 beta 2 nAChR antagonist alpha-CTx PeIA probably reside within the three residues, which differ in loop 2, given their otherwise similar 3D structures. alpha 4/7-CTx LvIA is a new, potent, selective alpha 3 beta 2 nAChR antagonist, which will enable detailed studies of alpha 3 beta 2 nAChR structure, function, and physiological roles.-Luo, S., Zhangsun, D., Schroeder, C. I., Zhu, X., Hu, Y., Wu, Y., Weltzin, M. M., Eberhard, S., Kaas, Q., Craik, D. J., McIntosh, J. M., Whiteaker, P. A novel alpha 4/7-conotoxin LvIA from Conus lividus that selectively blocks alpha 3 beta 2 vs. alpha 6/alpha 3 beta 2 beta 3 nicotinic acetylcholine receptors.