TY - JOUR
T1 - Enterococcus faecalis glutathione reductase
T2 - purification, characterization and expression under normal and hyperbaric O2 conditions
AU - Patel, Mehul P.
AU - Marcinkeviciene, Jovita
AU - Blanchard, John S.
N1 - Funding Information:
This work was supported by NIH Grant GM33449 and the Molecular Biophysics Training Program GM08572.
PY - 1998/9/1
Y1 - 1998/9/1
N2 - Glutathione reductase is found ubiquitously in eukaryotes and Gram-negative bacteria, and plays a significant role in bacterial defense against oxidative stress. Glutathione reductase from the Gram-positive bacterium Enterococcus faecalis was purified to homogeneity using anion exchange, hydrophobic interaction, and affinity chromatography. The homogeneous 49-kDa enzyme contained 1 mol bound FAD per subunit. The determined N-terminal amino acid sequence of the E. faecalis enzyme displays significant identity with glutathione reductases from other Gram-negative and Gram-positive bacteria, as well as yeast and human erythrocyte reductases. The kinetic mechanism is ping-pong, and the determined kinetic parameters exhibited by the E. faecalis glutathione reductase are similar to those found for glutathione reductases from yeast, Escherichia coli, and human erythrocyte. A two-fold increased expression of glutathione reductase activity and a three-fold induction of glutathione peroxidase activity were observed under hyperbaric O2 growth conditions without a corresponding change in the total glutathione and soluble thiol content. The difference in the expression of the enzyme, and its cognate substrate's intracellular concentration, under these conditions suggest that the gene encoding glutathione reductase is responsive to oxygen concentration, but that the genes encoding the glutathione synthesizing enzymes are not linked to an oxygen-sensitive promoter. Copyright (C) 1998 Federation of European Microbiological Societies.
AB - Glutathione reductase is found ubiquitously in eukaryotes and Gram-negative bacteria, and plays a significant role in bacterial defense against oxidative stress. Glutathione reductase from the Gram-positive bacterium Enterococcus faecalis was purified to homogeneity using anion exchange, hydrophobic interaction, and affinity chromatography. The homogeneous 49-kDa enzyme contained 1 mol bound FAD per subunit. The determined N-terminal amino acid sequence of the E. faecalis enzyme displays significant identity with glutathione reductases from other Gram-negative and Gram-positive bacteria, as well as yeast and human erythrocyte reductases. The kinetic mechanism is ping-pong, and the determined kinetic parameters exhibited by the E. faecalis glutathione reductase are similar to those found for glutathione reductases from yeast, Escherichia coli, and human erythrocyte. A two-fold increased expression of glutathione reductase activity and a three-fold induction of glutathione peroxidase activity were observed under hyperbaric O2 growth conditions without a corresponding change in the total glutathione and soluble thiol content. The difference in the expression of the enzyme, and its cognate substrate's intracellular concentration, under these conditions suggest that the gene encoding glutathione reductase is responsive to oxygen concentration, but that the genes encoding the glutathione synthesizing enzymes are not linked to an oxygen-sensitive promoter. Copyright (C) 1998 Federation of European Microbiological Societies.
KW - Enterococcus faecalis
KW - Glutathione reductase
KW - Oxidative stress
KW - Thiol content
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U2 - 10.1016/S0378-1097(98)00325-5
DO - 10.1016/S0378-1097(98)00325-5
M3 - Article
C2 - 9741094
AN - SCOPUS:0031656590
SN - 0378-1097
VL - 166
SP - 155
EP - 163
JO - FEMS Microbiology Letters
JF - FEMS Microbiology Letters
IS - 1
ER -