金属离子对LDH的抑制作用与底物对其保护作用研究

The studies of inhibitions of metallic ions and protections of substrates to LDH

采用紫外光谱测定方法,分析比较了Fe3＋,Cu2＋,Ni2＋,Co2＋4种金属离子在0.5~2.5mmol·L-1的浓度范围内对LDH活性的影响,其抑制作用程度次序为Fe3＋〉〉Cu2＋〉Ni2＋≈Co2＋.研究了在Fe3＋,Cu2＋,Ni2＋,Co2＋作抑制剂时,丙酮酸钠和NADH对酶的保护作用.结果表明,丙酮酸钠对LDH具有明显的保护作用,NADH则没有体现类似的保护作用.Cu2＋对LDH的抑制作用有不可逆抑制成分,Fe3＋对酶的抑制机制可能是可逆抑制.

The inhibitions of Fe3＋,Cu2＋,Ni2＋,Co2＋ within the scope of 0.5 mmol·L-1 to 2.5 mmol·L-1 on the lactate dehydrogenase were researched through UV-analysis.The results of inhibitions were Fe3＋Cu2＋Ni2＋≈Co2＋.When these metallic ions were present as inhibitors,the protective effection of pyruvate and NADH to the enzyme had also been studied.The protective effection of pyruvate was obvious,but NADH did not reflect the similar protective effection.The inhibition of Cu2＋ was irreversible in some extent,and Fe3＋ had a better reversible inhibition properties on LDH.