1axh: Difference between revisions

[[Image:1axh.gif|left|200px]]<br /><applet load="1axh" size="350" color="white" frame="true" align="right" spinBox="true"  

A family of potent insecticidal toxins has recently been isolated from the venom of Australian funnel web spiders. Among these is the 37-residue peptide omega-atracotoxin-HV1 (omega-ACTX-HV1) from Hadronyche versuta. We have chemically synthesized and folded omega-ACTX-HV1, shown that it is neurotoxic, ascertained its disulphide bonding pattern, and determined its three-dimensional solution structure using NMR spectroscopy. The structure consists of a solvent-accessible beta-hairpin protruding from a disulphide-bonded globular core comprising four beta-turns. The three intramolecular disulphide bonds from a cystine knot motif similar to that seen in several other neurotoxic peptides. Despite limited sequence identity, omega-ACTX-HV1 displays significant structural homology with the omega-agatoxins and omega-conotoxins, both of which are vertebrate calcium channel antagonists; however, in contrast with these toxins, we show that omega-ACTX-HV1 inhibits insect, but not mammalian, voltage-gated calcium channel currents.

1AXH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Hadronyche_versuta Hadronyche versuta]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AXH OCA].  

[[Category: Donoghue, S I.O.]]

[[Category: Fletcher, J I.]]

[[Category: King, G F.]]

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