Akademik Veri Yönetim Sistemi
JOURNAL OF ENZYME INHIBITION AND MEDICINAL CHEMISTRY, cilt.27, sa.1, ss.18-23, 2012 (SCI-Expanded)
The effects of ketotifen, meloxicam, phenyramidol-HCl and gadopentetic acid on the enzyme activity of GR were studied using human erythrocyte glutathione reductase (GR) enzymes in vitro. The enzyme was purified 209-fold from human erythrocytes in a yield of 19% with 0.31 U/mg. The purification procedure involved the preparation of haemolysate, ammonium sulphate precipitation, 2 '',5'-ADP Sepharose 4B affinity chromatography and Sephadex G-200 gel filtration chromatography. Purified enzyme was used in the in vitro studies. In the in vitro studies, IC50 values and K-i constants were 0.012 mM and 0.0008 +/- 0.00021 mM for ketotifen; 0.029 mM and 0.0061 +/- 0.00127 mM for meloxicam; 0.99 mM and 0.4340 +/- 0.0890 mM for phenyramidol-HCl; 138 mM and 28.84 +/- 4.69 mM for gadopentetic acid, respectively, showing the inhibition effects on the purified enzyme. Phenyramidol-HCl showed competitive inhibition, whereas the others showed non-competitive inhibition.