title: Cyclosporin G and metabolite binding to cyclophilin and a 50-kDa binding protein related to in vitro immunosuppression.
abstract: Seven purified metabolites of cyclosporin G (CsG) were studied for binding to cyclophilin and a 50-kDa binding protein (50-kDa BP). The ratios of the metabolite dissociation constants with respect to CsG were compared with in vitro immunosuppression by using the primary mixed lymphocyte suppression assay. The immunosuppressive potency ratio of the parent compounds, both cyclosporin A (CsA) and CsG, compared favorably with the drug dissociation constants for cyclophilin and the 50-kDa BP. Three of the seven metabolites had comparable binding and potency ratios for the 50-kDa BP. In contrast, none of the seven metabolites appreciably bound to cyclophilin in the concentration range tested.
authors.affiliation: Department of Biology, Catholic University of America, Washington, DC.
authors.forename: J G
authors.initials: JG
authors.lastname: Donnelly
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.forename: R W
authors.initials: RW
authors.lastname: Yatscoff
authors.forename: K R
authors.initials: KR
authors.lastname: Copeland
authors.forename: E W
authors.initials: EW
authors.lastname: Palaszynski
authors.forename: S J
authors.initials: SJ
authors.lastname: Soldin
mesh_terms: D000591:Amino Acid Isomerases / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002417:Cattle; D002460:Cell Line; D016572:Cyclosporine / Q000378:metabolism; D003524:Cyclosporins / Q000378:metabolism*; D007165:Immunosuppression Therapy; D007959:Lymphocyte Culture Test, Mixed; D008970:Molecular Weight; D019696:Peptidylprolyl Isomerase; D011485:Protein Binding
chemical_list: D002352:Carrier Proteins; D003524:Cyclosporins; C045571:cyclosporin G; D016572:Cyclosporine; D000591:Amino Acid Isomerases; D019696:Peptidylprolyl Isomerase