Effects of some antibiotics on glutathione reductase from bovine erythrocytes

Abstract

This paper describes effects of some antibiotics on glutathione reductase in vitro. Glutathione reductase was purified from bovine erythrocytes. Purification procedure consisted of four steps; preparation of hemolysate, ammonium sulphate precipitation, 2',5'-ADP Sepharose 4B affinity chromatography and Sephadex G-200 gel filtration chromatography. As a result of these four consecutive procedures, the enzyme having the specific activity of 62.5 EU/mg proteins was purified 31 250-fold with a yield of 11.39%. The purified enzyme showed a single band on sodium dodecyl sulfate polyacrilamide gel electrophoresis (SDS-PAGE). The effects of eight different antibiotics-streptomycin sulphate, gentamicin sulphate, netilmicin, teicoplanine, thiamphenicol, ampicillin, cefotaxime, and cefodizime- were investigated on the purified enzyme. Six of these antibiotics (streptomycin sulphate, gentamicin sulphate, netilmicin, teicoplanine, thiamphenicol, and ampicillin) increased the activity of glutathione reductase with increase in their concentrations while the two (cefotaxime and cefodizime) inhibited the enzyme activity. I50 values were 7.713 mM and 1.954 mM, and Ki constants were 11.011 mM and 8.956 mM for cefotaxime and cefodizime, respectively. Their inhibition types were competitive.