1mr6
From Proteopedia
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Solution Structure of gamma-Bungarotoxin:Implication for the role of the Residues Adjacent to RGD in Integrin Binding
Overview
Gamma-bungarotoxin, a snake venom protein isolated from Bungarus, multicinctus, contains 68 amino acids, including 10 cysteine residues and, a TAVRGDGP sequence at positions 30-37. The solution structure of, gamma-bungarotoxin has been determined by nuclear magnetic resonance (NMR), spectroscopy. The structure is similar to that of the short-chain, neurotoxins that contain three loops extending from a disulfide-bridged, core. The tripeptide Arg-Gly-Asp (RGD) sequence is located at the apex of, the flexible loop and is similar to that of other RGD-containing proteins., However, gamma-bungarotoxin only inhibits platelet aggregations with an, IC50 of 34 microM. To understand its weak activity in inhibiting platelet, aggregation, we mutated the RGD loop sequences of rhodostomin, a potent, platelet aggregation inhibitor, from RIPRGDMP to TAVRGDGP, resulting in a, 196-fold decrease in activity. In addition, the average Calpha-to-Calpha, distance between R33 and G36 of gamma-bungarotoxin is 6.02 A, i.e., shorter than that of other RGD-containing proteins that range from 6.55 to, 7.46 A. These results suggested that the amino acid residues flanking the, RGD motif might control the width of the RGD loop. This structural, difference may be responsible for its decrease in platelet aggregation, inhibition compared with other RGD-containing proteins.
About this Structure
1MR6 is a Single protein structure of sequence from Bungarus multicinctus. Full crystallographic information is available from OCA.
Reference
Solution structure of gamma-bungarotoxin: the functional significance of amino acid residues flanking the RGD motif in integrin binding., Shiu JH, Chen CY, Chang LS, Chen YC, Chen YC, Lo YH, Liu YC, Chuang WJ, Proteins. 2004 Dec 1;57(4):839-49. PMID:15390258
Page seeded by OCA on Tue Nov 20 21:38:49 2007
