南方鲶肝超氧化物歧化酶的分离纯化及部分性质研究

Extraction and Purification of Superoxide Dismutase (SOD) from the Liver of Silurus meridionnalis and Study of Its Properties

经热变性,丙酮分级沉淀,DEAE-琼脂糖离子交换层析和Superdex-200凝胶层析,从南方鲶肝中分离纯化获得超氧化物岐化酶.该酶的比活为806.84U/mg,提纯倍数为336.18,分子量为46.0kD,亚基分子量为15.2kD.该酶在20～60℃温度范围内稳定性较好,在pH4～8范围内活性稳定,对H2O2敏感,对KCN不敏感.Mg2+,Fe2+离子对该酶有激活作用,Zn2+,Pb2+,Ca2+,Cd+离子对该酶有抑制作用.

Superoxide dismustase （SOD） was extracted and purified from Silurus meridionnalis by denaturization with heating, grading precipitation with acetone, DEAE-sepharose chromatography and Superdex S-200 gel filtration. Its specific activity was 806.84 U/mg, and the purification fold was 336.18. Superdex S-200 chromatography and SDS-PAGE showed that the molecular weight of this enzyme was 46.0 kD, and the weight of the subunit was 15.2 kD. Its isoelectric point was 4.8 and it exhibited one absorption maximum in the ultraviolet at 275nm. This enzyme was stable in heat condition and in pH 4-8, insensitive to KCN and sensitive tO H2O2. Mg^2＋ and Fe^2＋ activated the enzyme while Zn^2, Pb^2＋, Ca^2＋ and Cd^＋ inhabited its activity.