β-Glucuronidase Catalyzed Hydrolysis of Benzo[ a ]pyrene-3-Glucuronide and Binding to DNA

Abstract
β-Glucuronidase catalyzes the hydrolysis of benzo[ a ]pyrene-3-glucuronide to 3-hydroxybenzo[ a ]pyrene. During the enzymatic hydrolysis, a benzo[ a ]pyrene derivative is formed which binds to DNA to a far greater extent than either the 3-hydroxybenzo[ a ]pyrene or its glucuronide. These results suggest that conjugates of benzo[ a ]pyrene may be converted by β-glucuronidase at intracellular and organ sites distal to the initial sites of oxygenation and conjugation of benzo[ a ]pyrene to activated intermediates that are possibly carcinogenic.