Effects of Metal Ions on the Activity of GOD from Penicillium amagasakiense

Effects of metal ions on the activity of GOD from Penicillium amagasakiense were studied.The results showed that Na+,K+,Ca2+,Pb2+ and Mn2+ effected lightly on the enzyme activity,while Al3+ and Zn2+ enhanced the enzyme activity lightly.Ag+,Hg2+,Mg2+,Cd2+,Cu2+ and Co2+ inhibited the enzyme activity.Ag+,Cu2+ and Hg2+ inhibited it obviously.They were potential potent inhibitor,and the inhibitor′s concentration leading to 50% of enzyme activity lost(IC50) for Ag+,Cu2+ and Hg2+ were estimated to be 0.08,10.0 and 31.25 μmol/L,respectively.The inhibitory kinetics and mechanism of Ag+ on the enzyme were studied.It showed that the inhibition of Ag+ to GOD was reversible and competitive.The inhibition constant(KI) was determined to be 0.065 μmol/L.The data from this study can be useful to the application of GOD.