1. Aspartic acid mutagenesis of αO-Conotoxin GeXIVA isomers reveals arginine residues crucial for inhibition of the α9α10 nicotinic acetylcholine receptor.
- Author
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Luo A, He J, Yu J, Wu Y, Harvey PJ, Kasheverov IE, Kudryavtsev DS, McIntosh JM, Tsetlin VI, Craik DJ, Zhangsun D, and Luo S
- Subjects
- Animals, Rats, Nicotinic Antagonists chemistry, Nicotinic Antagonists pharmacology, Molecular Dynamics Simulation, Mutagenesis, Isomerism, Conotoxins chemistry, Conotoxins genetics, Conotoxins pharmacology, Receptors, Nicotinic genetics, Receptors, Nicotinic metabolism, Receptors, Nicotinic chemistry, Arginine chemistry, Aspartic Acid chemistry, Aspartic Acid genetics
- Abstract
The two most active disulfide bond isomers of the analgesic αO-conotoxin GeXIVA, namely GeXIVA[1, 2] and GeXIVA[1, 4], were subjected to Asp-scanning mutagenesis to determine the key amino acid residues for activity at the rat α9α10 nicotinic acetylcholine receptor (nAChR). These studies revealed the key role of arginine residues for the activity of GeXIVA isomers towards the α9α10 nAChR. Based on these results, additional analogues with 2-4 mutations were designed and tested. The analogues [T1A,D14A,V28K]GeXIVA[1, 2] and [D14A,I23A,V28K]GeXIVA[1, 4] were developed and showed sub-nanomolar activity for the α9α10 nAChR with IC
50 values of 0.79 and 0.38 nM. The latter analogue had exceptional selectivity for the α9α10 receptor subtype over other nAChR subtypes and can be considered as a drug candidate for further development. Molecular dynamics of receptor-ligand complexes allowed us to make deductions about the possible causes of increases in the affinity of key GeXIVA[1, 4] mutants for the α9α10 nAChR., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2024
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