人尿苷二磷酸葡醛酸转移酶1A6重组酶对酚类和羧酸类化合物与葡醛酸结合的催化活性

目的利用杆状病毒系统表达的人尿苷二磷酸葡醛酸转移酶(UGT)1A6重组酶对一些化合物进行葡醛酸结合研究,以筛选或验证UGT1A6重组酶的底物。方法采用HPLC法对底物或代谢物进行检测,并根据底物的减少来计算该酶对各底物的酶动力学参数。结果人UGT1A6重组酶能很好地催化α-萘酚、β-萘酚和儿茶酚的葡醛酸结合,但对托特罗定、对乙酰氨基酚、水杨酸、对氨基水杨酸、槲皮素、山奈酚、异鼠李素、扁桃酸、布洛芬和萘普生无明显催化活性。结论人UGT1A6重组酶对平面的简单酚类化合物有明显的催化活性,但对结构复杂的酚类或羧酸类化合物活性不明显。

Catalytic activities of recombinant human uridine 5′-diphosphate glucuronosyltransferases 1A6 on glucuronidation of phenols and carboxylic compounds

AIM To screen or validate the substrates of uridine 5′-diphosphate glucuronosyltransferases(UGT)1A6 with a recombinant human UGT1A 6 expressed by baculovirus expression system. METHODS Using HPLC to detect the substrates or metabolites, and calculating kinetic parameters of the recombinant UGT1A6 toward each compound. RESULTSThe recombinant human UGT1A6 could well catalyze α-naphthol, β-naphthol and catechol markedly, but could not catalyze tolterodine, acetaminophen, salicylic acid, p-aminosalicylic acid, quercetin, kaempferol, isorhamnetin, mandelic acid, ibuprofen and naproxen. CONCLUSION The recombinant human UGT1A6 can catalyze simple planar phenols, but not complex phenols or carboxylic compounds.