Kim S W, Lee S O, Lee T H
Department of Microbiology, College of Natural Science, Pusan National University, Korea.
Agric Biol Chem. 1991 Jan;55(1):101-8.
Superoxide dismutase (SOD) was purified from Aerobacter aerogenes IFO 3317 to an electrophoretically homogeneous state and partially characterized. SOD was purified by ammonium sulfate fractionation, column chromatography on DEAE-Sephadex A-50, gel filtration on Sephadex G-100, phenyl-Toyopearl 650 M hydrophobic chromatography, and hydroxyapatite adsorption chromatography. The molecular weight and subunit molecular weight of the purified enzyme were estimated to be 45,000 and 22,000, respectively. The isoelectric point of the enzyme was about pH 4.0. The purified enzyme remained stable at pH 7.0-11.0, 25 degrees C for 36 hrs, but was rapidly inactivated below pH 7.0. SOD was stable up to 35 degrees C at pH 7.0, but was inactivated at temperatures above that. The absorption maximum in the visible range was found at 360 nm, and the enzyme was insensitive to cyanide and fluoride, and sensitive to hydrogen peroxide and azide. These results suggest that the enzyme is an iron-containing SOD. The amino acid composition and the N-terminal sequence of the first 15 amino acids of the enzyme exhibited close homology with the other iron-containing SODs.
超氧化物歧化酶（SOD）从产气气杆菌IFO 3317中纯化至电泳纯状态，并进行了部分特性鉴定。通过硫酸铵分级沉淀、DEAE-葡聚糖A-50柱色谱、葡聚糖G-100凝胶过滤、苯基-托普雷斯650M疏水色谱和羟基磷灰石吸附色谱对SOD进行纯化。纯化酶的分子量和亚基分子量分别估计为45,000和22,000。该酶的等电点约为pH 4.0。纯化酶在pH 7.0 - 11.0、25℃下36小时保持稳定，但在pH 7.0以下迅速失活。在pH 7.0时，SOD在高达35℃时稳定，但在高于该温度时失活。在可见光范围内最大吸收峰出现在360nm处，该酶对氰化物和氟化物不敏感，对过氧化氢和叠氮化物敏感。这些结果表明该酶是一种含铁的SOD。该酶的氨基酸组成和前15个氨基酸的N端序列与其他含铁SOD具有密切的同源性。
