This old version of Proteopedia is provided for student assignments while the new version is undergoing repairs. Content and edits done in this old version of Proteopedia after March 1, 2026 will eventually be lost when it is retired in about June of 2026.
Apply for new accounts at the new Proteopedia. Your logins will work in both the old and new versions.
1hvw
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /><applet load="1hvw" size="450" color="white" frame="true" align="right" spinBox="true" caption="1hvw" /> '''HAIRPINLESS MUTANT OF OMEGA-ATRACOTOXIN-HV1A...)
Next diff →
Revision as of 14:44, 20 November 2007
|
HAIRPINLESS MUTANT OF OMEGA-ATRACOTOXIN-HV1A
Overview
omega-Atracotoxin-Hv1a is an insect-specific neurotoxin whose phylogenetic, specificity derives from its ability to antagonize insect, but not, vertebrate, voltage-gated calcium channels. In order to help understand, its mechanism of action and to enhance its utility as a lead compound for, insecticide development, we used a combination of protein engineering and, site-directed mutagenesis to probe the toxin for key functional regions., First, we constructed a Hairpinless mutant in which the C-terminal, beta-hairpin, which is highly conserved in this family of neurotoxins, was, excised without affecting the fold of the residual disulfide-rich core of, the toxin. The Hairpinless mutant was devoid of insecticidal activity, indicating the functional importance of the hairpin. We subsequently, developed a highly efficient system for production of recombinant toxin, and then probed the hairpin for key functional residues using, alanine-scanning mutagenesis followed by a second round of mutagenesis, based on initial "hits" from the alanine scan. This revealed that two, spatially proximal residues, Asn(27) and Arg(35), form a contiguous, molecular surface that is essential for toxin activity. We propose that, this surface of the beta-hairpin is a key site for interaction of the, toxin with insect calcium channels.
About this Structure
1HVW is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
Functional significance of the beta hairpin in the insecticidal neurotoxin omega-atracotoxin-Hv1a., Tedford HW, Fletcher JI, King GF, J Biol Chem. 2001 Jul 13;276(28):26568-76. Epub 2001 Apr 19. PMID:11313356
Page seeded by OCA on Tue Nov 20 16:51:34 2007
