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Publications [#113109] of Harold P. Erickson

Papers Published

  1. T David-Pfeuty, HP Erickson, D Pantaloni, Guanosinetriphosphatase activity of tubulin associated with microtubule assembly., Proceedings of the National Academy of Sciences of the United States of America, UNITED STATES, vol. 74 no. 12 (December, 1977), pp. 5372-6, ISSN 0027-8424
    (last updated on 2009/02/12)

    Abstract:
    Tubulin, purified by cycles of assembly followed by phosphocellulose chromatography, exhibits a characteristic GTPase activity that is polymerization dependent and can be attributed to the tubulin itself. This activity has been observed, in a standard reassembly buffer containing low Mg2+, under three conditions that induce microtubule assembly: in the presence of microtubule-associated proteins, in the presence of DEAE-dextran, or after addition of high Mg2+ and glycerol. The phosphocellulose-purified tubulin showed no GTPase activity under the following nonpolymerizing conditions: in buffer with low Mg2+ in the absence of microtubule-associated proteins or DEAE-dextran, in buffer with high Mg2+ and glycerol at tubulin concentrations below the critical concentration, or when microtubule assembly was inhibited by vinblastine. Colchicine, on the other hand, while blocking microtubule assembly, induced a significant GTPase activity in the phosphocellulose-purified tubulin. During the process of assembly, GTP appears to be hydrolyzed as a free tubulin dimer polymerizes into a microtubule. A constant GTPase activity when polymerization equilibrium is reached apparently reflects the cyclic polymerization-depolymerization of tubulin dimers at the ends of the microtubules.

    Keywords:
    Animals • Brain • Chromatography, Ion Exchange • Colchicine • GTP Phosphohydrolases • Glycoproteins • Guanosine Triphosphate • Kinetics • Microtubules • Phosphoric Monoester Hydrolases • Swine • Tubulin • Vinblastine • enzymology • enzymology* • isolation & purification • metabolism • metabolism* • pharmacology


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