A novel superoxide dismutase from Cicer arietinum L. seedlings: isolation, purification and characterization.
Superoxide dismutase is an important enzyme with various therapeutic applications. Search of a new source of superoxide dismutase with novel properties has significant importance. The current work reports purification of a novel superoxide dismutase enzyme with unique characteristics. A copper zinc superoxide dismutase (Cu-Zn SOD) was purified and characterized from Cicer arietinum L. seedlings germinated under aluminium (Al+3) stress. The specific activity of purified protein was 158 units/mg with 28 fold purification. The superoxide dismutase is a homodimeric protein with approx subunit molecular weight of 33.27 kDa. The enzyme is identified as Cu-Zn category of superoxide dismutase, reflected by H2O2 induced inhibition of in-gel activity and presence of quantifiable copper and zinc ions. The optimum pH range for purified Cu-Zn SOD activity was observed within 6.5-8.5 (highest at pH 8.0) and the pH stability was in the range of 6.0-8.5. The enzyme was more stable at low temperature (below 30°C) and the Km of purified Cu-Zn SOD for riboflavin as substrate was 10.16 ± 2.5 µM. The N-terminal amino acid sequence showed homology at conserved residues with other plant Cu-Zn SODs.
Centre for Environment, Indian Institute of Technology Guwahati, Guwahati, Assam, 781039, India.
Sushant
S
Singh
Abhay Narayan
AN
Singh
Anil
A
Verma
Vikash Kumar
VK
Dubey
D000595:Amino Acid Sequence; D029863:Cicer / Q000737:chemistry / Q000201:enzymology*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D063347:Native Polyacrylamide Gel Electrophoresis; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D012256:Riboflavin; D036226:Seedlings / Q000737:chemistry / Q000201:enzymology; D013482:Superoxide Dismutase / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D013696:Temperature
D010940:Plant Proteins; D013482:Superoxide Dismutase; D012256:Riboflavin