猪肉中AMP脱氨酶的分离纯化及其特性研究

Characterization and purification of AMP deaminase from pork

摘要: 从生鲜猪肉中分离提纯AMP脱氨酶（AMPD）,并对其性质进行了研究。将猪肉AMP脱氨酶的初提物经磷酸纤维素层析、Q-Sepharose Fast Flow层析及5’-AMP琼脂糖层析等纯化步骤,得到经聚丙烯酰胺凝胶电泳为单一蛋白质区带的酶液。提纯倍数为133.68,酶液比活力2.5U/mg。利用凝胶过滤法测定酶的相对分子量为178ku,SDS-PAGE测定酶的亚基相对分子量为87ku。酶的等电点为6.81。酶催化AMP脱氨反应的最适pH为5.9,pH在5.2⁶.4的范围内稳定。最适温度为37℃,高于42℃时不稳定。不同来源的AMP脱氨酶其激活剂及抑制剂基本一致。

Abstract: An AMPD was purified from fresh pork by following procedures:Cellulose phosphate chromatography, Q -Sepharose Fast Flow chromatography and 5’-AMP Sepharose chromatography. The preparation was formed a single band on SDS-PAGE. The purification multiple was 133.68, and the specific activity 2.5U/mg. The molecular weight of AMP deaminase was 178ku determined with gel filtration and its subunit weight was 87ku determined with SDS-PAGE. Isoelectric focusing study showed that pI values of the enzyme were 6.81. This enzyme catalysis AMPD optimal pH of ammonia reaction were 5.9, pH in the range of 5.2～6.4 stability. The optimum temperature was 37℃, higher than 42℃ was not stable. AMP deaminased from different sources were basically the same activator and inhibitor.