title: Enhancement of stability of 7 beta,8 alpha-dihyroxy-9 alpha epoxybenzo(a)pyrene by complex formation with serum albumin.
abstract: The biologically active and chemically unstable metabolite of benzo(a)pyrene, 7 beta,8 alpha-dihydroxy-9 alpha, 10 alpha-epoxybenzo(a)pyrene (BPDE), binds to human serum albumin in aqueous solutions with an association constant of 2.6 X 10(5)M-1. At pH 7.2, 24 degrees C and in 5mM sodium cacodylate buffer solution, this binding increases the lifetime of the diol epoxide by a factor of nearly 3. It is suggested that the formation of such physical complexes with proteins having hydrophobic interiors or with lipids may provide a mechanism by which highly reactive metabolites are transported from the site of metabolic synthesis to biological target molecules (e.g., DNA), in a reactive aqueous environment.
mesh_terms: D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D001580:Benzopyrenes / Q000378:metabolism*; D004355:Drug Stability; D006801:Humans; D007700:Kinetics; D011485:Protein Binding; D012709:Serum Albumin / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001580:Benzopyrenes; D012709:Serum Albumin; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide