Heinämäki A A, Piha R S
Acta Chem Scand B. 1980;34(5):363-7. doi: 10.3891/acta.chem.scand.34b-0363.
Cysteine sulfinic acid decarboxylase (EC 4.1.1.29) was purified from calf brain by pH precipitation, ammonium sulfate fractionation, gel filtration and DEAE-Sephadex A-50 chromatography. The enzyme preparation decarboxylated both cysteine sulfinic acid and cysteic acid at all steps of the purification and the ratio of the velocity of decarboxylation of cysteine sulfinic acid to that of cysteic acid was constant, about 2, throughout the purification procedure. The pH optimum was 7.2 both for cysteine sulfinic acid and cysteic acid. The molecular weight of the enzyme was estimated at 65 000 using gel filtration on a Sephadex G-200 column. Its Km's were 0.9 mM for cysteine sulfinic acid and 1.6 mM for cysteic acid, with Vmax values of 60.5 and 33.5 nmol/h(mg protein), respectively.
通过pH沉淀、硫酸铵分级分离、凝胶过滤和DEAE-葡聚糖A-50柱色谱法从牛脑中纯化了半胱氨酸亚磺酸脱羧酶（EC 4.1.1.29）。在纯化的各个步骤中，该酶制剂均可使半胱氨酸亚磺酸和半胱氨酸脱羧，并且在整个纯化过程中，半胱氨酸亚磺酸脱羧速度与半胱氨酸脱羧速度之比恒定，约为2。半胱氨酸亚磺酸和半胱氨酸的最适pH均为7.2。使用Sephadex G-200柱进行凝胶过滤，估计该酶的分子量为65000。其对半胱氨酸亚磺酸的Km值为0.9 mM，对半胱氨酸的Km值为1.6 mM，Vmax值分别为60.5和33.5 nmol/h（mg蛋白）。
