NADPH-specific disulfide reductase that is active with bis-gamma-glutamylcystine has been purified 1,900-fold from Halobacterium halobium to yield a homogeneous preparation of the enzyme. Purification of this novel reductase, designated bis-gamma-glutamylcystine reductase (GCR), and purification of halobacterial dihydrolipoamide dehydrogenase (DLD) were accomplished with the aid of immobilized-metal-ion
一种具有双-γ-谷
氨酰胺基胱
氨酸活性的
NADPH特异的二
硫键还原酶已从嗜盐杆菌中纯化了1,900倍,以产生均一的
酶制剂。借助于固定化的
金属离子亲和色谱,在高盐缓冲液中完成了这种新颖的还原酶(称为双-γ-谷
氨酰胱
氨酸还原酶(GCR)的纯化和卤代细菌二氢脂酰胺脱氢酶(DLD)的纯化。GCR在含有1.23 M(NH4)2SO4的缓冲液中固定的Cu2 +
树脂和在含有4.0 M NaCl的缓冲液中固定的Ni2 +
树脂上进行色谱分离,可将纯度提高120倍。发现天然GCR是Mr 122,000的二聚体黄素蛋白,并且在离子强度很高的缓冲液中对热更稳定。在含有NaCl的缓冲液和含有(NH4)2SO4的缓冲液中,在固定化Cu2 +
树脂柱上进行DLD色谱分离,两种缓冲液中DLD的洗脱差异显着。已发现纯化的DLD是一种热稳定的二聚体黄素蛋白,分子量为120,000,对
NAD具有非常高的特异性。讨论了固定化
金属离子