Sulfhydryl groups of Mimosa pudica tubulin implicated in colchicine binding and polymerization in vitro.
The important characteristic of novel Mimosa pudica tubulin is its ability to bind colchicine only when dithiothreitol is included in the isolation buffer, indicating the involvement of sulfhydryl groups in colchicine binding. Modification of sulfhydryl groups by a sulfhydryl modifying agent also affects the normal assembly of tubulin into microtubules, as revealed by electron microscopic and spectrophotometric studies. The number of free sulfhydryl groups present in tubulin protein responsible for both colchicine binding and polymerization has been found to be 4, distributed in alpha and beta subunits, and is distinctly different from the number reported for animal tubulin.
Roychaudhuri
A
A
Department of Biochemistry, Bose Institute, Calcutta, India.
Biswas
S
S
D001665:Binding Sites; D003078:Colchicine / Q000378:metabolism*; D003703:Demecolcine / Q000378:metabolism; D004228:Dithionitrobenzoic Acid / Q000494:pharmacology; D005033:Ethylmaleimide / Q000378:metabolism; D007700:Kinetics; D046911:Macromolecular Substances; D008854:Microscopy, Electron; D008870:Microtubules / Q000378:metabolism / Q000648:ultrastructure; D010944:Plants / Q000378:metabolism*; D013438:Sulfhydryl Compounds / Q000032:analysis; D014404:Tubulin / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure
D046911:Macromolecular Substances; D013438:Sulfhydryl Compounds; D014404:Tubulin; D004228:Dithionitrobenzoic Acid; D005033:Ethylmaleimide; D003078:Colchicine; D003703:Demecolcine