Purification and biochemical characterization of a superoxide dismutase from the soluble fraction of the cyanobacterium, Spirulina platensis.

Krutika Desai; Subramanian Sivakami

Abstract  A superoxide dismutase (SOD) was purified from Spirulina platensis sonicate. The SOD was purified to homogeneity (48-fold and 0.24% yield) through ammonium sulphate precipitation and DEAE-52 anion exchange chromatography. The SOD from S. platensis appeared to be a homodimer with a molecular weight of 30 kDa and a subunit MW of 15 kDa as determined by both native polyacrylamide gel electrophoresis and mass spectrometry. The enzyme activity was stable at pH 6.5–10.0 and 50 �C. Using group-specific chemical modifying reagents, the amino acids arginine, histidine, tryptophan, tyrosine and aspartic acid were identified to be essential for S. platensis SOD activity. The amino acid composition was found to lack methionine and cysteine. The inhibition of activity by H2O2 suggests that the enzyme may be an iron containing SOD.

SUPEROXIDE dismutase; CHEMICAL purification; SPIRULINA; CYANOBACTERIA

World Journal of Microbiology & Biotechnology, 2007, Vol 23, Issue 12, p1661

0959-3993

Academic Journal

10.1007/s11274-007-9413-8