Kinoshita N, Gelboin H V
Science. 1978 Jan 20;199(4326):307-9. doi: 10.1126/science.619459.
beta-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 beta-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.
β-葡萄糖醛酸酶催化苯并[a]芘-3-葡萄糖醛酸酯水解生成3-羟基苯并[a]芘。在酶促水解过程中,会形成一种苯并[a]芘衍生物,它与DNA的结合程度远高于3-羟基苯并[a]芘或其葡萄糖醛酸酯。这些结果表明,苯并(a)芘的共轭物可能会被β-葡萄糖醛酸酶在细胞内和远离苯并(a)芘氧化和共轭初始位点的器官部位转化为可能具有致癌性的活性中间体。