Identification of Crucial Residues in α-Conotoxin EI Inhibiting Muscle Nicotinic Acetylcholine Receptor

Ning, Jiong; Ren, Jie; Xiong, Yang; Wu, Yong; Zhangsun, Manqi; Zhangsun, Dongting; Zhu, Xiaopeng; Luo, Sulan

doi:10.3390/toxins11100603

Cited by 8 publications

(7 citation statements)

References 34 publications

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“…RegIIA chemically synthesized is a potent antagonist of the α3β4 nAChRs in Xenopus laevis oocytes, moreover, it can also activate α3β2 and α7 nAChRs [ 23 ]. α-Conotoxin EI mainly blocks α1β1δε nAChRs, applying the alanine scanning, the inhibition of EI(S13A) synthesized using solid phase methods is increased in a 2-fold at α1β1δε nAChR [ 24 ]. α-Conotoxin TxID highly targets α3β4 nAChRs [ 25 ], and it also exhibits the inhibition of α6/α3β4 nAChR, but TxID(S9K) selectively inhibited α3β4 nAChR [ 26 ].…”

Section: Introductionmentioning

confidence: 99%

α-Conotoxin as Potential to α7-nAChR Recombinant Expressed in Escherichia coli

Li¹,

Yin²,

Song³

et al. 2020

Marine Drugs

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α7 nicotinic acetylcholine receptors (nAChR) is an important nicotinic acetylcholine receptors subtype and closely associated with cognitive disorders, such as Alzheimer’s and schizophrenia disease. The mutant ArIB (V11L, V16A) of α-conotoxin ArIB with 17-amino acid residues specifically targets α7 nAChR with no obvious effect on other nAChR subtypes. In the study, the synthetic gene encoding mature peptide of ArIB and mutant ArIB (V11L, V16A) carried a fusion protein Trx and 6 × His-tag was separately inserted in pET-32a (+) vector and transformed into Escherichia coli strain BL21(DE3) pLysS for expression. The expressions of Trx-ArIB-His6 and Trx-ArIB (V11L, V16A)-His6 were soluble in Escherichia coli, which were purified by Ni-NTA affinity chromatography column and cleaved by enterokinase to release rArIB and rArIB (V11L, V16A). Then, rArIB and rArIB (V11L, V16A) were purified by high-performance liquid chromatography (HPLC) and identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Bioactivity of rArIB and rArIB (V11L, V16A) was assessed by two-electrode voltage-clamp electrophysiology in Xenopus laevis oocytes expressing human nAChR subtypes. The results indicated that the yield of the fusion proteins was approximately 50 mg/L and rArIB (V11L, V16A) antagonized the α7 nAChR subtype selectively with 8-nM IC50. In summary, this study provides an efficient method to biosynthesize α-conotoxin ArIB and rArIB (V11L, V16A) in Escherichia coli, which could be economical to obtain massively bioactive disulfide-rich polypeptides at fast speed.

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Section: Introductionmentioning

confidence: 99%

α-Conotoxin as Potential to α7-nAChR Recombinant Expressed in Escherichia coli

Li¹,

Yin²,

Song³

et al. 2020

Marine Drugs

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“…Binding assays revealed that this α-conotoxin selectively binds the α/δ site of Torpedo nAChRs, and, although this is also its preferred site in mammalian receptors, EI can also bind the α/γ site in the latter [ 85 ]. It has been recently shown that: (i) the point mutations of residues His7, Pro8, Met12, and Pro15 into alanine significantly reduced the effect of EI on α1β1δε nAChRs; (ii) the replacement of a critical serine residue at position 13 by alanine increased the potency of the toxin against this muscle-type nAChR while reducing its effect on the neuronal α3β2 and α3β4 subtypes; and (iii) the potency against α1β1δε nAChRs was related to the Arg1-Asn2-Hyp3 residues at the N-terminus of the toxin, as the deletion of these residues in the analogue △1-3 EI caused total loss of effect on this subtype [ 93 ].…”

Section: Conus Ermineusmentioning

confidence: 99%

Cone snail species off the Brazilian coast and their venoms: a review and update

Fiorotti

Figueiredo

Campos

et al. 2023

J. Venom. Anim. Toxins incl. Trop. Dis

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The genus Conus includes over 900 species of marine invertebrates known as cone snails, whose venoms are among the most powerful described so far. This potency is mainly due to the concerted action of hundreds of small bioactive peptides named conopeptides, which target different ion channels and membrane receptors and thus interfere with crucial physiological processes. By swiftly harpooning and injecting their prey and predators with such deadly cocktails, the slow-moving cone snails guarantee their survival in the harsh, competitive marine environment. Each cone snail species produces a unique venom, as the mature sequences of conopeptides from the venoms of different species share very little identity. This biochemical diversity, added to the numerous species and conopeptides contained in their venoms, results in an immense biotechnological and therapeutic potential, still largely unexplored. That is especially true regarding the bioprospection of the venoms of cone snail species found off the Brazilian coast - a region widely known for its biodiversity. Of the 31 species described in this region so far, only four - Conus cancellatus , Conus regius , Conus villepinii , and Conus ermineus - have had their venoms partially characterized, and, although many bioactive molecules have been identified, only a few have been actually isolated and studied. In addition to providing an overview on all the cone snail species found off the Brazilian coast to date, this review compiles the information on the structural and pharmacological features of conopeptides and other molecules identified in the venoms of the four aforementioned species, paving the way for future studies.

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“…Mutagenesis in the β2 subunit revealed three residues (T59, V111, F119) that maximally affect the affinity (both increase and decrease) of α-conotoxin LvIA towards the α3β2 receptor [ 163 ]. Alanine-scanning mutagenesis has also been carried out recently for some “muscle” α-conotoxins, which identified the residues determining their selectivity to the α1β1εδ nAChR [ 164 , 165 ]. Similarly, the residues important for selective targeting of the α3β4 and α3β2 receptors were identified as a result of alanine-scanning mutagenesis of α-conotoxin RegIIA [ 130 ].…”

Section: Marine Origin Peptides Targeting Nachrsmentioning

confidence: 99%

Marine Origin Ligands of Nicotinic Receptors: Low Molecular Compounds, Peptides and Proteins for Fundamental Research and Practical Applications

et al. 2022

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The purpose of our review is to briefly show what different compounds of marine origin, from low molecular weight ones to peptides and proteins, offer for understanding the structure and mechanism of action of nicotinic acetylcholine receptors (nAChRs) and for finding novel drugs to combat the diseases where nAChRs may be involved. The importance of the mentioned classes of ligands has changed with time; a protein from the marine snake venom was the first excellent tool to characterize the muscle-type nAChRs from the electric ray, while at present, muscle and α7 receptors are labeled with the radioactive or fluorescent derivatives prepared from α-bungarotoxin isolated from the many-banded krait. The most sophisticated instruments to distinguish muscle from neuronal nAChRs, and especially distinct subtypes within the latter, are α-conotoxins. Such information is crucial for fundamental studies on the nAChR revealing the properties of their orthosteric and allosteric binding sites and mechanisms of the channel opening and closure. Similar data are provided by low-molecular weight compounds of marine origin, but here the main purpose is drug design. In our review we tried to show what has been obtained in the last decade when the listed classes of compounds were used in the nAChR research, applying computer modeling, synthetic analogues and receptor mutants, X-ray and electron-microscopy analyses of complexes with the nAChRs, and their models which are acetylcholine-binding proteins and heterologously-expressed ligand-binding domains.

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Identification of Crucial Residues in α-Conotoxin EI Inhibiting Muscle Nicotinic Acetylcholine Receptor

Cited by 8 publications

References 34 publications

α-Conotoxin as Potential to α7-nAChR Recombinant Expressed in Escherichia coli

α-Conotoxin as Potential to α7-nAChR Recombinant Expressed in Escherichia coli

Cone snail species off the Brazilian coast and their venoms: a review and update

Marine Origin Ligands of Nicotinic Receptors: Low Molecular Compounds, Peptides and Proteins for Fundamental Research and Practical Applications

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