摘要
本实验以大豆为原料,经硫酸铵沉淀、葡聚糖凝胶柱G200分离沉淀,得到2种脂肪氧合酶(LOX):LOX-1,LOX-2。对这两种同工酶的部分特性进行研究。其中LOX-1的反应最适pH为7.0,在pH9.0时无活性。而LOX-2最适pH为9.0,在pH7.0时也表现出较强活性。最适温度均为25℃。两种同工酶的热稳定性结果表明,LOX-1和LOX-2在40℃活性稳定,加热温度高于50℃时,活性急剧下降。在亚油酸为底物的反应体系中,LOX-1和LOX-2的Km值分别为8.2、12.2mmol/L。并对Ca2+、Na+、Cu2+、和Fe3+等不同的金属离子表现出不同的反应活性。
Lipoxygenase (LOX) from soybean was isolated and purified by Sephadex G-200 column chromatography. There were two LOX fraction obtained: LOX -1, LOX-2. The specific activities were increased to 5-fold and 9-fold, respectively. The optimum pH for LOX-1 was 7.0 whereas the LOX-2 was 9.0. The LOX-1 and Lox -2 had a same optimum temperature 25 ℃.LOX isozymes had a similar thermal stability. The isozymes were heat stable up to 40 ℃, but were rapidly inactivity by 30 rain incubation at temperature higher than 50 ℃. The apparent Km values of LOX-1 and Lox-2 for LOX- LA (linoleic acid) were 8.2 m mol/L and 12.2m molL, respectively. The isozymes of LOX revealed different reaction with the metal ions like Ca2+, Na+, Cu2+, and Fe3+.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2008年第9期396-398,共3页
Food Science
关键词
大豆
脂肪氧合酶
同功酶
纯化
特性
soybean
lipoxygenase
isoenzyme
purification
property