北京鸭红细胞超氧化物歧化酶—分离纯化和性质

采用氯仿—乙醇分级分离,丙酮沉淀以及DE-32纤维素柱层析的方法,从北京鸭红细胞中分离得到纯的铜锌超氧化物歧化酶(Cu·Zn-SOD)。4升鸭血红细胞的SOD制品总活力为375,400u,比活力为13,410u/mg蛋白,回收率为64％。 铜锌超氧化物歧化酶制品呈淡蓝绿色,最大紫外吸收波长为258nm。测得该酶分子量为32,000,亚基分子量为16,000。该酶亚基由150个氨基酸残基组成,不含色氨酸,并测得它的N—末端氨基酸为丙氨酸。

Copper/Zinc Superoxide Dismutase from Peking Duck Erythrocytes-Purification and Properties

Copper/zinc superoxide dismutase from Peking Duck erythrocytes has been purified by chloroform-ethanol fractionation, acetone precipitation and DE-32 chromatography. The purified enzyme obtained from four liters of Peking Duck blood possesses a total activity of 375,400 units with specific activity of 13,410 units per mg protein. The yield is 64%.The enzyme prepared by this procedure shows a pale blue-green color. It exhibits one absorption maximum in the ultraviolet at 258nm. The molecular weight of the purified enzyme is 32,000 daltons as determined with gel filtration on Sephadex G-75, that of the enzyme subunit is 16,000 daltons as estimated with sodium dodecyl sulp-hate-polyacrylamide gel electrophoresis. The enzyme subunit consists of 150 amino acid residues, from which tryptophan is absent. The N-terminal of the enzyme subunit is alanine as assayed by dansyl chloride.