中国对虾酸性和碱性磷酸酶的特性研究

STUDIES ON THE CHARACTERISTICS OF ACID AND ALKALINE PHOSPHATASES IN CHINESE SHRIMP, PEN AEUS CHIN EN SIS

磷酸酶,又称正磷酸单酯水解酶,是一种能催化各种含磷化合物水解的酶类,根据它们起催化作用的最适pH特性,又可分为酸性磷酸酶(EC 3.1.32)和碱性磷酸酶(EC3.1.31)两类。磷酸酶具有非常重要的生理功能,它广泛存在于各种动物体内,是动物体内重要的解毒体系,并且在动物机体的骨化过程及在磷化物和其它一些营养物质的消化、吸收和转运过程中都起着重要作用。此外,通过催化磷蛋白的水解,磷酸酶在细胞调节过程中也具有一定作用。尽管磷酸酶的研究有很久的历史,但绝大多数的研究几乎都集中在陆生的高等脊椎动物哺乳类身上。在无脊椎动物体中这方面研究的很少,而有关甲壳类动物磷酸酶的研究文献几乎没有。

Study of acid and alkaline phosphatases from muscle and hepatopancreas of the Chinese shrimp, Penaeus ehinensis collected from the Huangdao Marine Bioecology Experimental Station, Intitute of Oceanology, Academia Sinica showed that the pH optimum of the AcPase isozyme (Ⅰ,Ⅱ, Ⅲ) from the muscle were 2.6, 4.3, 5.8 and slightly different with different drawing methods, there were no peaks within the limits of pH alkalinity; that the temperature optima were 45℃, 50℃, 40℃, the thermostabilities were in the order Ⅱ>Ⅰ>Ⅲ; that the pH optima of the AcPase isozyme (Ⅰ',Ⅱ') and AlPase (Ⅲ') from the hepatopancreas were 3.4, 6.5, 9.5; and that the temperature optima were 35℃,38℃,40℃ and the thermostabilities were in the order Ⅲ' > Ⅰ' > Ⅱ'. In addition, Michaelis constants (Km), maximum velocity activators and inhibitors such as DTT, 2-merca ptoethanol, 2-mercaptodiethanol, formaldehyde solution, cysteine, phenylalanine, tartrate, iodoacetate, ascorbic acid, oxalic acid, thiourea, EDTA, Ba2+,Ca2+,Cd2+,Co2+,Cu2+,Fe2+,Mg2+,Mn2+, Pb2+, Sr2+, Zn2+, Al3+,Cr3+,Fe3+,Se4+ on phosphatases of the shrimp were investigated.