Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Investigation of the Highly Active Manganese Superoxide Dismutase from Saccharomyces cerevisiae

Journal Article · · Journal of the American Chemical Society
OSTI ID:992127
Manganese superoxide dismutase (MnSOD) from different species differs in its efficiency in removing high concentrations of superoxide (O{sub 2}{sup -}), due to different levels of product inhibition. Human MnSOD exhibits a substantially higher level of product inhibition than the MnSODs from bacteria. In order to investigate the mechanism of product inhibition and whether it is a feature common to eukaryotic MnSODs, we purified MnSOD from Saccharomyces cerevisiae (ScMnSOD). It was a tetramer with 0.6 equiv of Mn per monomer. The catalytic activity of ScMnSOD was investigated by pulse radiolysis and compared with human and two bacterial (Escherichia coli and Deinococcus radiodurans) MnSODs. To our surprise, ScMnSOD most efficiently facilitates removal of high concentrations of O{sub 2}{sup -} among these MnSODs. The gating value k{sub 2}/k{sub 3} that characterizes the level of product inhibition scales as ScMnSOD > D. radiodurans MnSOD > E. coli MnSOD > human MnSOD. While most MnSODs rest as the oxidized form, ScMnSOD was isolated in the Mn{sup 2+} oxidation state as revealed by its optical and electron paramagnetic resonance spectra. This finding poses the possibility of elucidating the origin of product inhibition by comparing human MnSOD with ScMnSOD.
Research Organization:
BROOKHAVEN NATIONAL LABORATORY (BNL)
Sponsoring Organization:
DOE - Office Of Science
DOE Contract Number:
AC02-98CH10886
OSTI ID:
992127
Report Number(s):
BNL--91392-2010-JA
Journal Information:
Journal of the American Chemical Society, Journal Name: Journal of the American Chemical Society Journal Issue: 36 Vol. 132; ISSN JACSAT; ISSN 0002-7863
Country of Publication:
United States
Language:
English