Discovery, Characterization, and Engineering of LvIC, an alpha 4/4-Conotoxin That Selectively Blocks Rat alpha 6/ alpha 3 beta 4 Nicotinic Acetylcholine Receptors.
Zhu, X., Wang, S., Kaas, Q., Yu, J., Wu, Y., Harvey, P.J., Zhangsun, D., Craik, D.J., Luo, S.(2023) J Med Chem 66: 2020-2031
- PubMed: 36682014 
- DOI: https://doi.org/10.1021/acs.jmedchem.2c01786
- Primary Citation of Related Structures:  
8FLP - PubMed Abstract: 
α6β4 nicotinic acetylcholine receptors (nAChRs) are expressed in the central and peripheral nervous systems, but their functions are not fully understood, largely because of a lack of specific ligands. Here, we characterized a novel α-conotoxin, LvIC, and designed a series of analogues to probe structure-activity relationships at the α6β4 nAChR. The potency and selectivity of these conotoxins were tested using two-electrode voltage-clamp recording on nAChR subtypes expressed in Xenopus laevis oocytes. One of the analogues, [D1G,ΔQ14]LvIC, potently blocked α6/α3β4 nAChRs (α6/α3 is a chimera) with an IC 50 of 19 nM, with minimal activity at other nAChR subtypes, including the structurally similar α6/α3β2β3 and α3β4 subtypes. Using NMR, molecular docking, and receptor mutation, structure-activity relationships of [D1G,ΔQ14]LvIC at the α6/α3β4 nAChR were defined. It is a potent and specific antagonist of α6β4 nAChRs that could potentially serve as a novel molecular probe to explore α6β4 nAChR-related neurophysiological and pharmacological functions.
Organizational Affiliation: 
School of Medicine, Guangxi University, Nanning 530004, China.