冷鲜牛肉高铁肌红蛋白还原酶的粗分离与性质

Preliminary Purification and Characterization of Metmyoglobin Reductase from Chilled Beef

以不同部位冷鲜牛肉(背最长肌、腰大肌)为原料,采用硫酸铵盐析法对其高铁肌红蛋白还原酶(Met Mb R)进行粗分离,并对分离所得酶液的适宜温度及p H进行研究,旨在为提高冷鲜牛肉的肉色稳定性奠定基础。结果表明,原料冷鲜牛背最长肌和牛腰大肌粗酶液的分子量主要范围均为14.3~97.2 k Da。原料冷鲜牛背最长肌高铁肌红蛋白还原酶酶活为94.33 U/m L,在70%硫酸铵饱和度下可主要沉淀得高铁肌红蛋白还原酶,从而达到粗分离的目的。粗分离所得的牛背最长肌高铁肌红蛋白还原酶适宜温度30~45℃,适宜p H 6.5。原料冷鲜牛腰大肌高铁肌红蛋白还原酶酶活为53.60 U/m L,在70%硫酸铵饱和度下可主要沉淀得高铁肌红蛋白还原酶,从而达到粗分离的目的。粗分离所得的牛腰大肌高铁肌红蛋白还原酶适宜温度35℃,适宜p H 6.0~6.5。

Using two parts of chilled beef(longissimus dorsi and psoas major)as raw materials,preliminary investigate the purification and characteristics of metmyoglobin reductase.The crude enzyme solution of chilled beef was extracted,and then the metmyoglobin reductase was simply purified with ammonium sulfate precipitation.The suitable temperature and p H of the metmyoglobin reductase were determined.SDS-PAGE analysis revealed that the molecular weight of the crude enzyme from longissimus dorsi and psoas major was 14.3-97.2 k Da,mainly.The results indicated that the metmyoglobin reductase activity of longissimus dorsi and psoas major was 94.33 U/m L and 53.60 U/m L,separately.The metmyoglobin reductase could be crudly purified with ammonium sulfate(70%saturation).The suitable temperature of the metmyoglobin reductase from longissimus dorsi was 30-45℃,with the suitable p H 6.5.The suitable temperature of the metmyoglobin reductase from lpsoas major was 35℃,with the suitable p H 6.0-6.5.