title: Studies on non-covalent associations of immunosuppressive drugs with serum albumin using pneumatically assisted electrospray ionization mass spectrometry.
abstract: Pneumatically assisted electrospray ionization (ion-spray) mass spectrometry was employed in the detection of non-covalent interactions of immunosuppressive drugs with proteins. Non-covalent complexes of albumin (rat and bovine) with FK506, dihydro-FK506, and FK520 were observed. No complexation was detected between albumin and cyclosporin A (CsA), even at a protein-ligand molar ratio of 1:20. It is suggested that the lack of detection of an albumin-CsA non-covalent complex may be attributed to dissociation of the weakly associated species during ion vaporization. Nonetheless, preliminary results indicate that ion-spray mass spectrometry has potential in qualitative evaluation of drug-plasma protein interaction.
authors.affiliation: Department of Drug Metabolism (I), Merck Research Laboratories, Rahway, New Jersey 07065-0900.
authors.forename: R
authors.initials: R
authors.lastname: Bakhtiar
authors.forename: R A
authors.initials: RA
authors.lastname: Stearns
mesh_terms: D000818:Animals; D002417:Cattle; D016572:Cyclosporine / Q000737:chemistry / Q000378:metabolism; D007166:Immunosuppressive Agents / Q000097:blood*; D013058:Mass Spectrometry; D011485:Protein Binding; D051381:Rats; D012709:Serum Albumin / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000737:chemistry; D016559:Tacrolimus / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D007166:Immunosuppressive Agents; D012709:Serum Albumin; D012710:Serum Albumin, Bovine; D016572:Cyclosporine; C058028:immunomycin; D016559:Tacrolimus