Structural highlights
Function
SCXN1_MESEU Alpha toxins bind voltage-independently at site-3 of sodium channels (Nav) and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission. This toxin inhibits inactivation of Nav1.6/SCN8A (EC(50)=3.1 uM) and drosophila DmNav1 (EC(50)=1.17 uM) (PubMed:21969612, Ref.2). The toxin (1 uM) does not significantly shift the midpoint of activation at the two channels, but induces a significant depolarizing shift in the V(1/2) of inactivation of the channels (PubMed:21969612).[1] [PROSITE-ProRule:PRU01210]
Publication Abstract from PubMed
Old world scorpions produce an abundance of toxins called alpha-NaTx, which interfere with the fast inactivation of voltage-gated sodium channels. Their selectivity to channels of mammals or insects depends on a part of toxin named the specificity module. We report here the spatial structure of a major and broadly active toxin MeuNaTxalpha-1 from the venom of Mesobuthus eupeus. Notably, its specificity module is markedly different from other alpha-NaTx with known 3D structure. Close inspection shows that its conformation is a result of an interplay between protein motifs such as the nest and niche, which eventually shape alpha-NaTx structural diversity.
Structure of MeuNaTxalpha-1 toxin from scorpion venom highlights the importance of the nest motif.,Mineev KS, Kuzmenkov AI, Arseniev AS, Vassilevski AA Proteins. 2021 Mar 13. doi: 10.1002/prot.26074. PMID:33713480[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Zhu S, Peigneur S, Gao B, Lu X, Cao C, Tytgat J. Evolutionary diversification of Mesobuthus {alpha}-scorpion toxins affecting sodium channels. Mol Cell Proteomics. 2011 Oct 3. PMID:21969612 doi:10.1074/mcp.M111.012054
- ↑ Mineev KS, Kuzmenkov AI, Arseniev AS, Vassilevski AA. Structure of MeuNaTxalpha-1 toxin from scorpion venom highlights the importance of the nest motif. Proteins. 2021 Mar 13. doi: 10.1002/prot.26074. PMID:33713480 doi:http://dx.doi.org/10.1002/prot.26074
