Direct photoaffinity labeling of tubulin with colchicine.

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Wolff J, Knipling L, Cahnmann HJ, Palumbo G

Direct photoaffinity labeling of tubulin with colchicine.

Proc Natl Acad Sci U S A. 1991 Apr 1;88(7):2820-4.

PubMed ID

2011590 [ View in PubMed

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Abstract

Ultraviolet irradiation of the [3H]colchicine-tubulin complex leads to direct photolabeling of tubulin with low but practicable efficiency. The bulk (70% to greater than 90%) of the labeling occurs on beta-tubulin and appears early after irradiation, whereas alpha-tubulin is labeled later. The labeling ratio of beta-tubulin to alpha-tubulin (beta/alpha ratio) is reduced by prolonged incubation, prolonged irradiation, urea, high ionic strength, the use of aged tubulin, dilution of tubulin, or large concentrations of colchicine or podophyllotoxin. Glycerol increases the beta/alpha ratio. Limited data with [3H]podophyllotoxin show that it covalently bound with a similar beta/alpha distribution. Vinblastine, on the other hand, exhibits preferential attachment to alpha-tubulin. The possibilities that colchicine binds at the interface between alpha-tubulin and beta-tubulin, that the drug spans this interface, and that both subunits may contribute to the binding site are suggested.

DrugBank Data that Cites this Article

Drug Targets

Drug	Target	Kind	Organism	Pharmacological Action	Actions
Podofilox	Tubulin beta chain	Protein	Humans	Yes	Inhibitor	Details