Title: Tubulin
Additional Names: Colchicine-binding protein
Literature References: The subunit protein of microtubules, which are large protein assemblies that play an important role in eukaryotic cell form determination and dynamics. Microtubules have the general structure of long hollow cylinders within which 13 protofilaments of tubulin are arranged in a parallel manner to the cylinder axis. The axial arrangement of the protofilaments with respect to each other results in the appearance of a helical structure, and the in vitro microtubule assembly process generally follows the laws of helical protein polymerization, cf. Thermodynamics of the Polymerization of Proteins, F. Oosawa, S. Asakura, Eds. (Academic Press, New York, 1975). Tubulin is an asymmetric dimer consisting of two nearly identical molecules, a-tubulin and b-tubulin, each having mol wts of about 55,000. The two molecules can be separated due to differences in electrophoretic mobilities. Isoln from mammalian brain using colchicine binding: R. C. Weisenberg et al., Biochemistry 7, 4466 (1968). Discovery of conditions for microtubule assembly in vitro: R. C. Weisenberg, Science 177, 1104 (1972); G. G. Borisy, J. B. Olmstead, ibid. 1196. Prepn of large quantities of brain tubulin through successive assembly-disassembly cycles: M. L. Shelanski et al., Proc. Natl. Acad. Sci. USA 70, 765 (1973). Purification of tubulin from rat pancreas: J. F. Launay et al., Biochem. Biophys. Res. Commun. 111, 253 (1983). Structure of two human a-tubulin genes: C. Wilde et al., Proc. Natl. Acad. Sci. USA 79, 96 (1982). Structure and arrangement of protofilaments in microtubules and tubulin sheets: B. F. McEwen, Diss. Abstr. B 43, 942 (1982). Series of articles on prepn, isoln, and purification of tubulin from various sources: Methods Enzymol. 85, Pt. B, 376-417 (1982). Reviews: J. A. Snyder, J. R. McIntosh, Annu. Rev. Biochem. 45, 699-720 (1976); S. N. Timasheff, L. M. Grisham, ibid. 49, 565-591 (1980); M. F. Carlier, Mol. Cell. Biochem. 47, 97-113 (1982).
Properties: Purified calf brain tubulin retains many of its in vivo biochemical characteristics, such as the ability to self-assemble into microtubules and the response of the assembly reaction to inhibitory effects of cold temperature, Ca2+, and anti-microtubule agents, e.g. vinblastine and colchicine, q.q.v. uv max (PG buffer): 278 nm (e 1.33 ml mg-1 cm-1).
Absorption maximum: uv max (PG buffer): 278 nm (e 1.33 ml mg-1 cm-1) |