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从厦门文昌鱼Branchiostoma belcheri(Gray)体内部分提纯一种酸性磷酸酶制剂。酶液比活力6.467μmole/mg prot/30min,提纯47倍,以等电聚焦法测其等电点为pH4.05。该酶在醋酸盐缓冲系统(37℃)中,以苯磷酸二钠为底物,测得最适pH4.5,K_m值为1.25×10~(-3)M(以对硝基苯磷酸二纳为底物测得最适pH4.5,K_m值为2.08×10~(-4)M)。pH影响K_m值而不影响V_(max),表现为竞争性类型。在不同温度条件下,测其活化能为9.15千卡/克分子。F~-,Hg~(2+),Mo~(6+)表现不同的抑制,PCMB终浓度为5×10~4M时酶活力下降70％。
An acid phosphatase preparation was partially purified from Xiamen amphioxus Branchiostoma belcheri (Gray). The specific activity of enzyme solution was 6.467μmole / mg prot / 30min, and the purification time was 47 times. The isoelectric point was pH4.05 by isoelectric focusing. The optimum pH value was found to be 4.5 and the Km value was 1.25 × 10 ~ (-3) M in acetate buffer system (37 ℃) using disodium phosphate as substrate. The optimum pH was 4.5 for buna as substrate, and the K_m was 2.08 × 10 ~ (-4) M. pH affects the K_m value without affecting V_ (max), showing a competitive type. Under different temperature conditions, the measured activation energy of 9.15 kcal / mole. F ~ -, Hg ~ (2 +) and Mo ~ (6+) showed different inhibition. When the final concentration of PCMB was 5 × 10 ~ 4M, the enzyme activity decreased by 70%.