背角无齿蚌碱性磷酸酶的功能基团研究

在一定条件下分别采用PMSF、DTT、PCMB、NBS、TNBS、SUAN、BrAc及IBr等化学修饰剂选择修饰背角无齿蚌碱性磷酸酶的多种氨基酸残基，并测定其酶活力变化。结果表明，PMSF、NBS、TNBS、SUAN、DTT的修饰能显著抑制酶的活力，活力的降低与修饰剂的浓度相关。BrAc、IAc、PCMB的修饰不表现对酶的抑制作用。作者初步认为，Ser、Lys和Trp残基是背角无齿蚌碱性磷酸酶的必需功能基团，部分二硫键时保护酶的催化功能也是必需的。

FUNCTIONAL GROUPS OF ALKALINE PHOSPHATASE FROM ANODONTA WOODIANA HEUDE

The alkaline phosphatase from Anodonta woodiana Heude was selectively modified by PMSF DTT, PCMB, NBS, TNBS, SUAN BrAc and IAc, and changes in the activities of the enzyne have been detected. The reachon of AKP with PMSF NBS,TNBS, SUAN and DTT resulted in a strong inhibition of the enzyme activities which decreased with the increase of modifier concentration. The bromoacetic acid, iodoacetic acid and p-chloromercuri-benzoic acid were found without any inhibition effect Studies of inactivation of AKP by chemical modification demostrated that Ser, Lys and Trp residues are indirpensble functional groups of the AKP. Partial disulfide bond are also for the function of this enzyme.