Ray, K. ; Bhattacharyya, B. ; Biswas, B. B. (1981) Role of B-ring of colchicine in its binding to tubulin Journal of Biological Chemistry, 256 (12). pp. 6241-6244. ISSN 0021-9258
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Official URL: http://www.jbc.org/content/256/12/6241.abstract?si...
Abstract
The chemical specificity of the colchicine-binding site of tubulin is less stringent for the presence of the B-ring than the A- and C-rings of colchicine, Colchicine analogues with modifications in the B-ring bind to tubulin at the same site as colchicine. Analogues with smaller or no substituents in the B-ring bind tubulin remarkably faster than colchicine. Thus, a compound without the B-ring [2-methoxy-5-(2',3',4'-trimethoxyphenyl)tropone] binds tubulin even at 4 °C and the binding is almost instantaneous at 37 °C. Colcemid and 2-methoxy-5-(2',3',4'-trimethoxyphenyl)tropone bind reversibly to tubulin, whereas colchicine and desacetamidocolchicine bind almost irreversibly, suggesting that the size of the B-ring moiety of colchicine is not related to the reversibility of binding. We conclude that although the presence of the B-ring of colchicine does not appear to be an essential prerequisite for the drug-tubulin interaction, the B-ring substituents play an important role in determining the binding properties of colchicine to tubulin.
Item Type: | Article |
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Source: | Copyright of this article belongs to American Society for Biochemistry and Molecular Biology. |
ID Code: | 26152 |
Deposited On: | 06 Dec 2010 13:00 |
Last Modified: | 17 May 2016 09:29 |
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