1wt8: Difference between revisions
New page: left|200px<br /><applet load="1wt8" size="450" color="white" frame="true" align="right" spinBox="true" caption="1wt8" /> '''Solution Structure of BmP08 from the Venom o... |
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'''Solution Structure of BmP08 from the Venom of Scorpion Buthus martensii Karsch, 20 structures'''<br /> | '''Solution Structure of BmP08 from the Venom of Scorpion Buthus martensii Karsch, 20 structures'''<br /> | ||
==Overview== | ==Overview== | ||
A novel short-chain scorpion toxin BmP08 was purified from the venom of | 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 Structure== | ==About this Structure== | ||
1WT8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mesobuthus_martensii Mesobuthus martensii]. Full crystallographic information is available from [http:// | 1WT8 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Mesobuthus_martensii Mesobuthus martensii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1WT8 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: alpha/beta scaffold]] | [[Category: alpha/beta scaffold]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:47:56 2008'' | ||
Revision as of 16:47, 21 February 2008
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Solution Structure of BmP08 from the Venom of Scorpion Buthus martensii Karsch, 20 structures
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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