Vinblastine photoaffinity labeling of a high molecular weight surface membrane glycoprotein specific for multidrug-resistant cells

A. R. Safa, C. J. Glover, M. B. Meyers, J. L. Biedler, R. L. Felsted

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Photoactive radioactive analogues of vinblastine were used to photoaffinity label membranes of Chinese hamster lung drug-sensitive (DC-3F), multidrug-resistant sublines selected for resistance to vincristine (DC-3F/VCRd-5L) or actinomycin D (DC-3F/ADX), and revertant (DC-3F/ADX-U) cells. A radiolabeled doublet (150-180 kDa) consisting of a major and minor band which was barely detectable in parental drug-sensitive cells was increased up to 150-fold in the drug-resistant variants but only 15-fold in the revertant cells. Photoaffinity labeling in the presence of 200-fold excess vinblastine reduced radiolabeling of the 150-180-kDa species up to 96%, confirming its Vinca alkaloid binding specificity. The radiolabeled doublet comigrated with a Coomassie Blue stained polypeptide doublet in the drug-resistant cells and was immunoprecipitated with polyclonal antibody which is specific for the 150-180-kDa surface membrane glycoprotein in multidrug-resistant cell lines. The identification of this Vinca alkaloid acceptor in multidrug-resistant plasma cell membranes suggests the possibility of a direct functional role for the 150-180-kDa surface membrane protein in the development of multidrug resistance.

Original languageEnglish (US)
Pages (from-to)6137-6140
Number of pages4
JournalJournal of Biological Chemistry
Issue number14
StatePublished - Dec 1 1986


ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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