Interaction of tubulin with drugs and alkylating agents. 1. Alkylation of tubulin by iodo[14C]acetamide and N,N'-ethylenebis(iodoacetamide)

Citations Over TimeTop 10% of 1981 papers

Abstract

The sulfhydryl groups of tubulin are reported to play a role in regulating microtubule assembly and colchicine binding to tubulin. The alkylating agents iodo[14C]acetamide and its bifunctional analogue N,N'-ethylenebis(iodoacetamide) are used as probes for the sulfhydryl groups of tubulin. In the presence of 8 M urea, alpha- and beta-tubulin have 10-11 and 8 alkylatable sulfhydryls, respectively, and one of the high molecular weight proteins (HMW 2) has 5 sulfhydryls/Mr 271 000. In the absence of urea, the rates of alkylation of alpha- and beta-tubulin are significantly lower but that of HMW 2 is unaffected. The sulfhydryls of tubulin are masked in intact microtubules. N,N'-Ethylenebis(iodoacetamide) reacts with free tubulin to generate a band, designated beta, which migrates ahead of beta on polyacrylamide gels. beta appears to represent a form of beta-tubulin containing at least one intrachain cross-link between sulfhydryl groups. Formation of beta* is inhibited in intact microtubules and is abolished if tubulin is denatured by 8 M urea, 1% sodium dodecyl sulfate, or boiling. N,N'-Ethylenebis(iodoacetamide) may thus be used as a probe for the native conformation of free tubulin.

Related Papers

• → Detection of Disulfide Bonds in Bovine Brain Tubulin and Their Role in Protein Folding and Microtubule Assembly in Vitro: A Novel Disulfide Detection Approach(2001)46 cited
• → The effects of the anilinonaphthalenesulfonates on the alkylation of tubulin: correlation between the appearance of sulfhydryl groups and apolar binding sites(1986)17 cited
• → Contrasting effects of maytansine and vinblastine on the alkylation of tubulin sulfhydryls(1981)51 cited
• → Reaction of Yeast Fatty Acid Synthetase with Iodoacetamide(1977)50 cited
• → Interaction of dolastatin 10 with bovine brain tubulin(1992)37 cited