BRUCE P. MAY AND PATRICK P. DENNIS* .... MAY AND DENNIS. TABLE 1. Purification ..... also thank Stanya Horsky for metal analysis and Sandy Kielland for.
Vol. 169, No. 4
JOURNAL OF BACTERIOLOGY, Apr. 1987, p. 1417-1422 0021-9193/87/041417-06$02.00/0 Copyright C 1987, American Society for Microbiology
Superoxide Dismutase from the Extremely Halophilic Archaebacterium Halobacterium cutirubrum BRUCE P. MAY AND PATRICK P. DENNIS*
Department
of Biochemistry,
University of British Columbia, Vancouver, British Columbia, Canada V6T I WS Received 22 September 1986/Accepted 15 December 1986
Halobacterium cutirubrum, a member of the archaebacteria, contains one superoxide dismutase (EC 1.15.1.1). This enzyme functions in the high-ionic-strength intracellular environment and protects the organism against the toxic effects of the superoxide anion. The enzyme has been purified to about 90% homogeneity by a four-step procedure which never removes it from conditions of high ionic strength. The subunits of the purified enzyme have a molecular weight of 25,000 and are possibly in tetrameric association. The enzyme shows anomalously high resistance to azide inhibition and sensitivity to inactivation by hydrogen peroxide. Metal analysis indicates 0.2 atom of Mn,
