1wt8
Solution Structure of BmP08 from the Venom of Scorpion Buthus martensii Karsch, 20 structures
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OverviewOverview
A novel short-chain scorpion toxin BmP08 was purified from the venom of, the Chinese scorpion Buthus martensi Karsch by a combination of, gel-filtration, ion exchange, and reversed-phase chromatography. The, primary sequence of BmP08 was determined using the tandem MS/MS technique, and Edman degradation, as well as results of NMR sequential assignments., It is composed of 31 amino acid residues including six cysteine residues, and shares less than 25% sequence identity with the known alpha-KTx, toxins. BmP08 shows no inhibitory activity on all tested voltage-dependent, and Ca(2+)-activated potassium channels. The 3D-structure of BmP08 has, been determined by 2D-NMR spectroscopy and molecular modeling techniques., This toxin adopts a common alpha/beta-motif, but shows a distinctive local, conformation and features a 3(10)-helix and a shorter beta-sheet. The, unique structure is closely related to the distinct primary sequence of, the toxin, especially to the novel arrangement of S-S linkages in the, molecule, in which two disulfide bridges (C(i)-C(j) and C(i+3)-C(j+3)), link covalently the 3(10)-helix with one strand of the beta-sheet, structure. The electrostatic potential surface analysis of the toxin, reveals salt bridges and hydrogen bonds between the basic residues and, negatively charged residues nearby in BmP08, which may be unfavorable for, its binding with the known voltage-dependent and Ca(2+)-activated, potassium channels. Thus, finding the target for this toxin should be an, interesting task in the future.
About this StructureAbout this Structure
1WT8 is a Single protein structure of sequence from Mesobuthus martensii. Full crystallographic information is available from OCA.
ReferenceReference
Solution structure of BmP08, a novel short-chain scorpion toxin from Buthus martensi Karsch., Chen X, Li Y, Tong X, Zhang N, Wu G, Zhang Q, Wu H, Biochem Biophys Res Commun. 2005 May 20;330(4):1116-26. PMID:15823559
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