毛细管电泳测定鸡肝二氢叶酸还原酶活力及其抑制剂的抑制率

Determination of Dihydrofolate Reductase Activity and the Inhibitory Rate of Its Inhibitors by Capillary Electrophoresis

本文采用毛细管电泳法对亲和层析提取的鸡肝二氢叶酸还原酶(DHFR)的反应体系进行了研究,根据体系中反应物还原辅酶Ⅱ(NADPH)和反应产物氧化型辅酶Ⅱ(NADP)的浓度变化,测得鸡肝二氢叶酸还原酶的米氏常数Km=1.35×10-5mol/L。将该体系用于鸡肝二氢叶酸还原酶抑制剂(DHFRIs)抑制率的测定,测得氨甲喋呤的半数抑制浓度(Ic50)为7.46×10-8mol/L。

Capillary electrophoresis （CE） has been applied to the study of the dihydrofolate reductase which was purified from chicken liver by affinity chr difference of peak areas between reactants （NADPH）and products（NADP） was us reaction system of omatography. The ed to determine the dynamic parameter Km of DHFR. The value of Km is 1.35×10^-5mol/L. The proposed CE method was used to determine the inhibition rate of methotrexate（MTX） to dihydrofolate reduetase. The Icso of MTX is 7.46×10^-8mol/L.