1mr6
From Proteopedia
(New page: 200px<br /><applet load="1mr6" size="450" color="white" frame="true" align="right" spinBox="true" caption="1mr6" /> '''Solution Structure of gamma-Bungarotoxin:Imp...) |
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'''Solution Structure of gamma-Bungarotoxin:Implication for the role of the Residues Adjacent to RGD in Integrin Binding'''<br /> | '''Solution Structure of gamma-Bungarotoxin:Implication for the role of the Residues Adjacent to RGD in Integrin Binding'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Gamma-bungarotoxin, a snake venom protein isolated from Bungarus | + | 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== | ==About this Structure== | ||
| - | 1MR6 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bungarus_multicinctus Bungarus multicinctus]. Full crystallographic information is available from [http:// | + | 1MR6 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bungarus_multicinctus Bungarus multicinctus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MR6 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bungarus multicinctus]] | [[Category: Bungarus multicinctus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Chang, L | + | [[Category: Chang, L S.]] |
| - | [[Category: Chen, C | + | [[Category: Chen, C Y.]] |
| - | [[Category: Chen, Y | + | [[Category: Chen, Y C.]] |
| - | [[Category: Chuang, W | + | [[Category: Chuang, W J.]] |
| - | [[Category: Shiu, J | + | [[Category: Shiu, J H.]] |
[[Category: neurotoxin]] | [[Category: neurotoxin]] | ||
[[Category: venom]] | [[Category: venom]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:58:11 2008'' |
Revision as of 11:58, 21 February 2008
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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
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