2e0h
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /><applet load="2e0h" size="350" color="white" frame="true" align="right" spinBox="true" caption="2e0h" /> '''Solution Structure of BmKalphaIT01, an alpha...)
Next diff →
Revision as of 10:52, 23 January 2008
|
Solution Structure of BmKalphaIT01, an alpha-insect toxin from the Venom of the Chinese Scorpion Buthus martensi Karsch
Overview
The solution structure of an alpha-insect toxin from Buthus martensii, Karsch, BmKalphaIT01, has been determined by two-dimensional NMR, spectroscopy and molecular modeling techniques. Combining the sequence, homology comparison and toxicity bioassays, BmKalphaIT01 has been, suggested to be a natural mutant of alpha-insect toxins and so can serve, as a tool to study the relationship of structure-function among this group, of toxins. The overall structure of BmKalphaIT01 shares a common core, structure consisting of an alpha-helix packed against a three-stranded, antiparallel beta-sheet, which exhibits distinctive local conformations, within the loops connecting these secondary structure elements. The, solution structure of BmKalphaIT01 features a non-proline cis peptide bond, between Asn9 and Tyr10, which is proposed to mediate the spatial closing, of the five-residue turn (Gln8-Cys12) and the C-terminal segment, (Arg58-His64) to form the NC domain and confer the toxin insect-specific, bioactivity. Conformational heterogeneity is observed in the solution of, BmKalphaIT01 and could be attributed to the cis-trans isomerization of the, peptide bond between residues 9 and 10. The minor conformation of, BmKalphaIT01 with a trans peptide bond between Asn9 and Tyr10 may be, responsible for its moderate bioactivity against mammals. The cis-trans, isomerization of the peptide bond between residues 9 and 10 may be the, structural basis of dual pharmacological activities of alpha-insect and, alpha-like scorpion toxins, which is supported by the fact that, conformational heterogeneity occurs in the solution structures of, LqhalphaIT, LqqIII, and LqhIII and by comparison of the solution structure, of BmKalphaIT01 with those of some relevant alpha-type toxins.
About this Structure
2E0H is a Single protein structure of sequence from Mesobuthus martensii. Full crystallographic information is available from OCA.
Reference
Solution Structure of BmKalphaIT01, an alpha-Insect Toxin from the Venom of the Chinese Scorpion Buthus martensii Karsch(,)., Tong X, Zhu J, Ma Y, Chen X, Wu G, He F, Cao C, Wu H, Biochemistry. 2007 Oct 9;46(40):11322-30. Epub 2007 Sep 18. PMID:17877370
Page seeded by OCA on Wed Jan 23 12:51:59 2008
