title: Competitive inhibition of colchicine binding to tubulin by microtubule-associated proteins.
abstract: Microtubule-associated proteins (MAPs) promote tubulin polymerization, whereas colchicine inhibits this process. In this paper, MAPs have been shown to inhibit colchicine binding to tubulin in a competitive manner. Attempts were made to identify which of the MAPs fraction(s) was responsible; both tau protein (a thermostable molecule with a molecular weight of approximately 70,000) and a high molecular weight fraction (HMW) were able to compete with colchicine. In contrast, Mg2+, which also induces microtubule assembly in vitro, had no effect on colchicine binding to tubulin.
mesh_terms: D000818:Animals; D001665:Binding Sites; D001667:Binding, Competitive; D001921:Brain; D003078:Colchicine / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008870:Microtubules / Q000378:metabolism*; D008970:Molecular Weight; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D011485:Protein Binding; D051381:Rats; D014404:Tubulin / Q000378:metabolism*
chemical_list: D006023:Glycoproteins; D009419:Nerve Tissue Proteins; D014404:Tubulin; D008274:Magnesium; D003078:Colchicine