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

FEBS Letters

Negri, Armando²  Palagi, Arianna¹  Colnaghi, Rita¹  Pagani, Silvia¹ 

[1] Dipartimento di Scienze Molecolari Agroalimentari, CISMI, The University of Milano, Via Celoria 2, I-20133 Milano, Italy;Istituto di Fisiologia Veterinaria e Biochimica, CISMI, The University of Milano, Milano, Italy

关键词: Superoxide dismutase;    Prokaryote;    Nitrogen-fixation;    Azotobacter vinelandii;    SOD;    superoxide dismutase;    Fe-SOD;    iron-containing superoxide dismutase;    Mn-SOD;    manganese-containing superoxide dismutase;    ICP;    ion-coupled plasma emission;   

DOI  :  10.1016/0014-5793(94)01339-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown