摘要
采用硫酸铵分级沉淀和柱层析的方法，从赤子爱胜蚓整体细胞抽提液内分离得到纯的铜锌超氧化物岐化酶（Ｃｕ，Ｚｎ－ＳＯＤ）。每１００ｇ蚯蚓得到的ＳＯＤ制品，总活力为１１１５０Ｕ，比活力为５１３８Ｕ／ｍｇ蛋白，回收率为２０％。铜锌超氧化物岐化酶呈淡蓝绿色，最大紫外吸收波长为２７０ｎｍ。测得该酶分子量为３３０００，亚基分子量为１６５００。该酶亚基由１５６个氨基酸残基组成，不含酪氨酸。
Copper/zinc superoxide dismutase from the cell extract of earthworm has been purified by ammonium sulfate precipitatiom and special column chromatographies. The purified enzyme obtained from 100 gram of tissue possesses a total activity of 11 500 units with specific activity of 5138 units per mg protein, The yield is 20%. The enzyme prepared by this procedure shows a pale blue-green color. It exhibits one absorption maximum in the ultraviolet at 270nm. The molecular weight of the purified enzyme is 33 000 daltons as determined with gel filtration on SephadexG-100,that of the enzyme subunits is 16 500 daltons as estimated with sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The enzyme subunit consists of 156 amino acid residues, from which tyrosine is absent.
