【摘要】 基因工程菌Y517#能表达醇醛脱氢酶,将L-山梨糖转化为VC的前体2-酮基-古龙酸(2-KGA)。通过超声波破碎菌体、硫酸铵分级沉淀、DEAE Sepharose FastFlow阴离子交换层析,Q Sepharose High Performance柱层析等过程,从Y517#发酵液中分离纯化了重组醇醛脱氢酶,纯化倍数为11倍。研究发现,该酶分子量为66kD,最适作用温度为40℃,对热不稳定,在60℃下保温10min酶活力完全丧失。最适pH值为7.0,pH稳定范围为6.0～9.0。更多还原

【Abstract】 L-sorbose/L-sorbosone dehydrogenase produced by gene engineering strain Y517# can transform L-sorbose to 2-KGA, the Vitamin C precursor. By means of ammonium sulfate precipitation, DEAE Sepharose Fast Flow and Q Sepharose High Performance assay, a purified recombinant L-sorbose/L-sorbosone dehydrogenase was obtained from Y517#. The results showed that the molecular weight of the purified enzyme is of 66 kD. The optimum temperature and pH are 40 ℃ and 7.0 respectivily. The enzyme activity is stable at pH 6.0～9.0 and below 45℃.更多还原