These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Different effects of tubulin ligands on the intrachain cross-linking of beta 1-tubulin.
    Author: Roach MC, Ludueña RF.
    Journal: J Biol Chem; 1984 Oct 10; 259(19):12063-71. PubMed ID: 6480599.
    Abstract:
    When bovine brain tubulin purified in the absence of GTP and MgCl2 is reacted with N,N'-ethylene-bis(iodoacetamide) (EBI), a bifunctional analogue of iodoacetamide, three new electrophoretically distinct species of tubulin are generated, migrating ahead of beta 1-tubulin on gels containing Na dodecyl sulfate. All three bands appear to be derived from the beta 1 subunit of tubulin and not from the alpha or beta 2 subunit. Accordingly, the bands have been designated beta 1 s, beta 1, and beta 1s in order of increasing electrophoretic mobility. EBI appears to introduce two intrachain cross-links into beta 1-tubulin; the beta 1s band contains one of these cross-links, designated beta s, the beta 1 band contains the other cross-link, designated beta s, and the beta 1 s band contains both cross-links. Both cross-links appear to involve sulfhydryl groups. Colchicine, podophyllotoxin, and nocodazole completely inhibit beta formation while GTP, vinblastine, and maytansine enhance it. It contrast, formation of beta s is completely blocked by guanine nucleotides and by maytansine, while vinblastine inhibits this by 70%. Colchicine, podophyllotoxin, and nocodazole enhance beta s formation. These results show that tubulin has the unusual property of having two discrete sites which can be targeted by an alkylating agent with each site having its alkylation inhibited by a different set of ligands. The results are consistent with several models, including one where vinblastine and maytansine have overlapping binding sites on the beta-subunit of tubulin relatively close to the GTP binding site.
    [Abstract] [Full Text] [Related] [New Search]