摘要
经Tris-HC l缓冲液(pH 8.6)抽提,正丁醇脱脂,硫酸铵分级沉淀分离,DEAE-Sepharose Fast F low和Sephacryl S-200柱层析,从黄鳝内脏中提取出电泳纯的碱性磷酸酶。用PCMB,NBS,PMSF,TNBS,SUAN,DTT及IAA在一定条件下选择性修饰该酶的各种氨基酸残基,并对酶活力的变化作出测定。结果表明,PMSF,NBS,TNBS,SUAN和DTT的修饰能显著抑制酶的活性,且酶活力降低程度与修饰剂的浓度相关;IAA和PCMB的修饰不表现对酶的抑制作用。初步认为,Ser,Lys和Trp残基为黄鳝碱性磷酸酶的必需功能基团,部分二硫键对保护酶的催化能力是必需的。
The amino acid residues of the alkaline phusphatase （AKP） from Monptenrus albus were selectively modified by PMSF, DTT, PCMB, NBS, TNBS, SUAN and IAc, and the changes in their activity were monitored, It was found that the reaction of AKP with PMSF, NBS, TNBS, SUAN and DTT resuhed in a strong inhibition of the enzyme activity, which decreased with the increase in modifier concentration. Modification by IAA and PCMB showed no inhibition to enzyme activity. It is thus tentatively assumed that Ser, Lys and Trp residues arc essential functional groups of AKP while partial disulfide bond is essential for the catalytic capacity of the protective enzyme.
出处
《西南农业大学学报（自然科学版）》
CSCD
北大核心
2005年第6期906-908,926,共4页
Journal of Southwest Agricultural University
基金
重庆市科委项目(2003-7852)
西南师范大学博士基金资助项目
关键词
黄鳝
碱性磷酸酶
功能基团
Monptenrus albus
alkaline phosphatase
functional group
