title: Competitive inhibition of photoaffinity labelling of P-glycoprotein by anticancer drugs and modulators including S9788.
abstract: The affinity of the multidrug resistance modulator S9788 to interact with P-glycoprotein was characterized by its ability to inhibit the photoaffinity labelling of plasma membranes of multidrug resistant chinese hamster ovary B30 cells by iodomycin. This iodinated analogue of daunomycin specifically photolabels P-glycoprotein in membrane vesicles as well as in intact cells. The multidrug resistance reversing agents verapamil and cyclosporin and the cytotoxic drugs vinblastine and daunomycin which are known to be recognized by P-glycoprotein competed with iodomycin for its binding site on P-glycoprotein. Vinblastine and cyclosporin bound with high affinity, S9788 and verapamil with medium affinity to P-glycoprotein.
authors.affiliation: Klinische Forschergruppe Molekulare Pathologie, Medizinischen Hochschule Hannover, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Demmer
authors.forename: T
authors.initials: T
authors.lastname: Dunn
authors.forename: T
authors.initials: T
authors.lastname: Hoof
authors.forename: P
authors.initials: P
authors.lastname: Kubesch
authors.forename: B
authors.initials: B
authors.lastname: Tümmler
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D006224:Cricetinae; D003630:Daunorubicin / Q000031:analogs & derivatives / Q000494:pharmacology; D018432:Drug Resistance, Multiple; D010880:Piperidines / Q000494:pharmacology*; D014227:Triazines / Q000494:pharmacology*
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D000970:Antineoplastic Agents; D010880:Piperidines; D014227:Triazines; C060588:iodomycin; C077022:S 9788; D003630:Daunorubicin