【摘要】 作者研究了对硫磷对人红细胞的Ca²⁺⁺—ATPase的抑制动力学。结果表明,在无对硫磷存在的情况下,正常对照 Ca²⁺⁺—ATPase的Km值为1.3×10^-4mol/L,Vmax为28.9nmol pi/mg蛋白/min,而当反应体系中有 2×10^-4～2×10（-3）mol/L对硫磷存在时,则Km增加为1.5～2.4×10^-4mol/L,Vmax却减小为27.3～18.46nmol pi/mg蛋白/min。用Hanes法作图结果提示,对硫磷对人红细胞Ca²⁺—ATPase 的抑制是一种混合性的抑制作用。更多还原

【Abstract】 The effects of parathion on enzyme kinetic catalyzed reactions of Ca2+-ATPase of human er ythrocyte membranes were studied. It is found that as the concentration of Parathion increasing the Km ( Michaelis-constant ) of Ca2+ -ATPase incresed, while the Vmax ( maxium velocity ) decrea sed. The inhibitor constant of parathion, Ki and Ki’, are 1.2×10-3 and 2.2 × 10-3mol/L respecti vely(Ki<Ki’) . Therefore, these results suggested that the inhibition of Ca2+ -ATPase activities of human erythrocyte membranes by parathion is a combination of competitive and noncompetitive nhibrtion, according to Hanes priciple.更多还原