Biomaterial Database

Effect of colchicine analogues on the dissociation of alpha beta tubulin into subunits: the locus of colchicine binding. 1994

K E Shearwin, and S N Timasheff

Graduate Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02254-9110.

A combination of ligand binding and sedimentation equilibrium studies was used to characterize the thermodynamic linkages between alpha beta tubulin association, nucleotide binding, and the interaction of colchicine analogues with dimeric and dissociated tubulins. The strength of binding of allocolchicine to the tubulin dimer was identical (8 x 10(5) M-1) whether the exchangeable nucleotide site (E site) was occupied by GTP or GDP. This drug bound to dimeric (alpha beta) tubulin and to one of the monomeric subunits, and the binding affinity for the dissociated state was linked to occupancy of the exchangeable nucleotide site. When the exchangeable site was occupied by GTP, the drug bound with very similar affinities to the dimeric and dissociated states of the protein. For tubulin-GDP, the binding of the drug to the dissociated state was significantly weaker (6.3 x 10(4) M-1) than to the dimeric state, suggesting the existence of an E-site-related conformational change in the dissociated state. Podophyllotoxin, which contains the A-ring portion of colchicine, bound with equal affinity to the dimeric and dissociated forms of both tubulin-GTP and tubulin-GDP, indicating that it is the C-ring portion of colchicine that is linked to the E-site-related conformational change.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D002417	Cattle	Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.	Beef Cow,Bos grunniens,Bos indicus,Bos indicus Cattle,Bos taurus,Cow,Cow, Domestic,Dairy Cow,Holstein Cow,Indicine Cattle,Taurine Cattle,Taurus Cattle,Yak,Zebu,Beef Cows,Bos indicus Cattles,Cattle, Bos indicus,Cattle, Indicine,Cattle, Taurine,Cattle, Taurus,Cattles, Bos indicus,Cattles, Indicine,Cattles, Taurine,Cattles, Taurus,Cow, Beef,Cow, Dairy,Cow, Holstein,Cows,Dairy Cows,Domestic Cow,Domestic Cows,Indicine Cattles,Taurine Cattles,Taurus Cattles,Yaks,Zebus
D003078	Colchicine	A major alkaloid from Colchicum autumnale L. and found also in other Colchicum species. Its primary therapeutic use is in the treatment of gout, but it has been used also in the therapy of familial Mediterranean fever (PERIODIC DISEASE).	Colchicine, (+-)-Isomer,Colchicine, (R)-Isomer
D006153	Guanosine Diphosphate	A guanine nucleotide containing two phosphate groups esterified to the sugar moiety.	GDP,Guanosine 5'-Diphosphate,Guanosine 5'-Trihydrogen Diphosphate,5'-Diphosphate, Guanosine,5'-Trihydrogen Diphosphate, Guanosine,Diphosphate, Guanosine,Diphosphate, Guanosine 5'-Trihydrogen,Guanosine 5' Diphosphate,Guanosine 5' Trihydrogen Diphosphate
D006160	Guanosine Triphosphate	Guanosine 5'-(tetrahydrogen triphosphate). A guanine nucleotide containing three phosphate groups esterified to the sugar moiety.	GTP,Triphosphate, Guanosine
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D013816	Thermodynamics	A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)	Thermodynamic
D014404	Tubulin	A microtubule subunit protein found in large quantities in mammalian brain. It has also been isolated from SPERM FLAGELLUM; CILIA; and other sources. Structurally, the protein is a dimer with a molecular weight of approximately 120,000 and a sedimentation coefficient of 5.8S. It binds to COLCHICINE; VINCRISTINE; and VINBLASTINE.	alpha-Tubulin,beta-Tubulin,delta-Tubulin,epsilon-Tubulin,gamma-Tubulin,alpha Tubulin,beta Tubulin,delta Tubulin,epsilon Tubulin,gamma Tubulin