摘要
对牛肉半腱肌中焦磷酸酶进行分离纯化并对其特性进行研究。将牛肉半腱肌用0.25mol/L蔗糖溶液冰浴匀浆后再用0.6mol/LNaCl提取、50%～70%饱和度硫酸铵分级沉淀、DEAE-52纤维素离子交换柱层析,得到纯的焦磷酸酶。通过SDS-PAGE分析,该酶的分子质量为72kD。实验进一步得出牛肉半腱肌中焦磷酸酶有较强的底物专一性,对底物焦磷酸四钠(PP)水解作用强。Mg2+是其激活剂,Ca2+、EDTA-Na2、EDTA-Na4抑制其酶活性。以PP为底物,测得该酶的初速度时间范围为25min,最适pH值为6.8,最适温度为47℃。
Pyrophosphatase （PPase） was isolated and purified from beef semitendinosus through homogenization with 0.25 mol/L sucrose, extraction with 0.6 mol/L NaCl solution, precipitation with 50% - 70% ammonium sulfate, and ion-exchange chromatography on DEAE-52 cellulose column. SDS-PAGE showed a single band with the relative molecular mass of 72 kD. This enzyme exhibited high substrate specificity to sodium pyrophosphate. Mg2＋ as an activator could promote the activity of pyrophosphatase; whereas, Ca2＋, EDTA-Na2 and EDTA-Na4 all exhibited an inhibitory effect on its activity. The optimal pH and temperature for reaction were 6.8 and 47 ℃, respectively.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2010年第5期160-164,共5页
Food Science
基金
农业部现代农业(牛肉)产业技术体系专项经费资助项目(MATS-BeefCattleSystem)
关键词
牛肉半腱肌
焦磷酸酶
分离纯化
特性
beef semitendinosus
pyrophosphatase
purification
property
