猪背最长肌焦磷酸酶的分离纯化与酶学特性  

Purification and Characterization of Pyrophosphatase from Pork longissimus dorsi Muscle

作　　者：靳红果[1] 万可慧[1] 田锐花[1] 彭增起[1] 王蓉蓉[1] 

机构地区：[1]南京农业大学教育部肉品加工与质量控制重点实验室,江苏南京210095

出　　处：《食品科学》2012年第3期168-173,共6页Food Science

摘　　要：通过离心、50%～70%饱和硫酸铵沉淀、DEAE-52离子交换柱层析,从猪背最长肌中分离纯化出焦磷酸酶(PPase)。变性聚丙烯酰胺凝胶电泳图谱显示,PPase分子质量约72kD。焦磷酸酶酶学特性研究表明,最适反应温度和pH值分别为50℃和7.5。Mg2+是PPase的激活剂,在浓度4.75mmol/L时,酶活力最强。但Na+和K+都能抑制酶的活力,且Na+的抑制效果强于K+。PPase水解焦磷酸钠(TSPP)的动力学参数Vmax为0.086μmol/(L.min)),Km为0.36mmol/L。Pyrophosphatase（PPase） from pork longissimus dorsi muscle was purified by ultracentrifugation,50%-70% saturated ammonium sulfate fractionation,DEAE-52 anion-exchange chromatography.The purified enzyme with molecular mass of 72 kD ran as a single band on SDS-polyacrylamide gel.The optimum pH and temperature for the isolated PPase was 7.5 and 50 ℃,respectively.Mg2＋ was necessary for PPase and the activity reached maximum at a concentration of 4.75 mmol/L.Na＋ and K＋ inhibited the enzyme activity and the inhibitory effect of Na＋ was stronger than K＋.The kinetic constant Km and Vmax using TSPP as substrate were determined as 0.36 mmol/L and 0.086μmol/（L·min）,respectively.

关 键 词：焦磷酸酶 纯化 酶学特性 猪肉 

分 类 号：TS251.1[轻工技术与工程—农产品加工及贮藏工程]