几种重金属离子对中华绒螯蟹N-乙酰-β-D-氨基葡萄糖苷酶活力的影响

EFFECTS OF SOME HEAVY METAL ON THE N-ACETYL-β-D-GLUCOSAMINIDASE FROM ERIOCHEIR SINENSIS

本文研究了Cu2+、Pb2+、Zn2+和Ag+等重金属离子对中华绒螯蟹(Eriocheir sinensis)N-乙酰-β-D-氨基葡萄糖苷酶(NAGase)活力的影响。其结果表明:Cu2+、Pb2+和Zn2+对酶活力有不同程度的抑制作用,Cu2+和Zn2+对酶的抑制作用均表现为非竞争性抑制类型,Cu2+和Zn2+对酶的抑制常数(KI)分别为1.25mmol/L和8.10mmo/L;Pb2+对酶的抑制作用表现为混合型抑制类型,其对酶的抑制常数KI与KIS分别为10.44mmol/L和2.18mmol/L。Ag+对酶的效应为先激活后抑制,其抑制作用表现为反竞争性抑制,Ag+对结合酶(ES)的抑制常数KIS为204.51mmol/L。

The effects of heavy metal ions(Cu2+,Pb2+,Zn2+ and Ag+)on N-Acetyl-β-D-glucosaminidase from Eriocheir sinensis were studied.The results showed that Cu2+,Pb2+ and Zn2+ inhibited the activity of enzyme in vary degree.Cu2+ and Zn2+ were both reversible non-competitive inhibitors.The inhibition constants of free enzyme(KI) of Cu2+ and Zn2+ were 1.25 mmol/L and 8.10mmol/L,respectively.Pb2+ was reversible mixed-type inhibition.The inhibition constants of free enzyme(KI) and enzyme-substrate complex(KIS) of Pb2+ w...