Open AccessThe interaction of cystamine with bovine brain tubulin
Author(s) -
BANERJEE Asok,
JORDAN Mary,
LITTLE Melvyn,
LUDUENA Richard F.
Publication year - 1987
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1987.tb11458.x
Subject(s) - cystamine , iodoacetamide , tubulin , chemistry , microtubule , biochemistry , biophysics , oxidizing agent , gtp' , stereochemistry , cysteine , enzyme , microbiology and biotechnology , biology , organic chemistry
Microtubule assembly in vitro is sensitive to a variety of non‐physiological sulfhydryl‐oxidizing agents, but the physiological significance of this phenomenon is unknown, since no physiological sulfhydryl‐oxidizing agent has been shown to affect microtubule assembly in vitro . We have accordingly investigated the interaction of tubulin with cystamine. We have found that millimolar concentrations of cystamine inhibit microtubule assembly and induce an abnormal form of tubulin polymerization. Cystamine‐induced polymerization does not occur at cold temperature. Formation of the polymer requires reaction of cystamine with two sulfhydryls which become available at 37°C. In addition, cystamine reacts with about three sulfhydryls at 0°C without inducing polymerization. This latter set of sulfhydryls appear to include one or both of the previously defined β s sulfhydryls whose reaction with N , N '‐ethylene‐bis(iodoacetamide) is markedly inhibited by GTP, maytansine and vinblastine [Roach, M. C. & Luduena, R. F. (1984) J. Biol. Chem. 259 , 12063–12071]. Cystamine's specific manner of interacting with tubulin suggests that it may mimic an endogenous sulfhydryl‐directed regulator of microtubule assembly.