从固氮棕色固氮菌中纯化和鉴定一种铁超氧化物歧化酶

Purification and characterization of an iron superoxide dismutase from the nitrogen-fixing Azotobacter vinelandii.

作者信息

Pagani S, Colnaghi R, Palagi A, Negri A

机构信息

Dipartimento di Scienze Molecolari Agroalimentari, CISMI, University of Milano, Italy.

出版信息

FEBS Lett. 1995 Jan 2;357(1):79-82. doi: 10.1016/0014-5793(94)01339-3.

DOI:10.1016/0014-5793(94)01339-3

PMID:8001685

Abstract

Two electrophoretically distinct forms of superoxide dismutase (SOD; EC 1.15.1.1) which show different inhibition patterns to hydrogen peroxide have been identified in Azotobacter vinelandii. The SOD inhibited by hydrogen peroxide was purified to homogeneity, and turned out to be an iron superoxide dismutase. The enzyme is present in only one molecular form with an isoelectric point of 4.1, and it is composed of two identical subunits with an apparent molecular weight of 21,000 Da. Spectroscopic analyses indicated that this enzyme contains ferric iron (1.4-1.6 mol/mol protein) in the typical high-spin form present in other prokaryotic Fe-SODs. N-Terminal sequence alignments (up to the 49th residue) showed that A. vinelandii Fe-SOD has high similarity with other prokaryotic Fe-SODs.

摘要

在棕色固氮菌中已鉴定出两种电泳性质不同的超氧化物歧化酶（SOD；EC 1.15.1.1）形式，它们对过氧化氢表现出不同的抑制模式。受过氧化氢抑制的SOD被纯化至同质，结果表明它是一种铁超氧化物歧化酶。该酶仅以一种分子形式存在，其等电点为4.1，由两个表观分子量为21,000 Da的相同亚基组成。光谱分析表明，该酶含有典型的高自旋形式的铁离子（1.4 - 1.6摩尔/摩尔蛋白质），存在于其他原核生物铁超氧化物歧化酶中。N端序列比对（至第49个残基）表明，棕色固氮菌铁超氧化物歧化酶与其他原核生物铁超氧化物歧化酶具有高度相似性。