【摘要】 研究几种抗菌药物对凡纳滨对虾壳膜N-乙酰-β-D-氨基葡萄糖苷酶(NAGase,EC 3.2.1.52)活力的影响.结果表明,诺氟沙星和磺胺甲噁唑对该酶活力有不同程度的抑制作用,盐酸环丙沙星对此酶有激活作用,而青霉素钾、链霉素、庆大霉素、卡那霉素、磺胺嘧啶等对酶活力基本上没有影响;磺胺甲噁唑的抑制作用最为显著,导致酶活力下降50%的抑制剂浓度(IC50)为0.094 mg/mL.抑制作用动力学研究结果表明,磺胺甲噁唑对酶的抑制作用为混合型可逆抑制,其抑制常数KI为5.98 mg/mL,对酶-底物络合物的抑制常数KIS为13.08 mg/mL.该研究对凡纳滨对虾的人工养殖具有一定的参考价值.更多还原

【Abstract】 The effects of some antibacterial medicines on the hydrolysis of pNP-NAG catalyzed by N-acetyl-β-D-glucosaminidase(NAGase,EC 3.2.1.52) from prawn(Litopenaeus vannamei) were studied.The results indicated that norfloxacin and acetylsulfamethoxazole could inhibit the enzyme activity in different extent,while penicilin,streptomycin,gentamicin,kanamycin and sulfadiazine had hardly any effects on the enzyme activity.The inhibitory effect of acetylsulfamethoxazole was the most potent.The value of IC50,the inhibitor concentrations leading to 50% enzyme activity lost,was estimated to be 0.094 mg/mL.The inhibitory kinetics of acetylsulfamethoxazole on the enzyme was further studied.The results showed that acetylsulfamethoxazole was reversible inhibitor of mixed-type,and the inhibition constants KI and KIS were determined to be 5.98 mg/mL and 13.08 mg/mL,respectively.更多还原