Effects of some metal ions on human erythrocyte glutathione reductase: an in vitro study.
In this study, we investigated inhibitory effects of some metal ions on human erythrocyte glutathione reductase. For this purpose, initially human erythrocyte glutathione reductase was purified 1051-fold in a yield of 41% by using 2', 5'-ADP Sepharose 4B affinity gel and Sephadex G-200 gel filtration chromatography. SDS polyacrylamide gel electrophoresis was done in order to control the purification of enzyme. SDS polyacrylamide gel electrophoresis showed a single band for enzyme. A constant temperature (4 degrees C) was maintained during the purification process. Enzyme activity was determined with the Beutler method by using a spectrophotometer at 340 nm. Hg(2+), Cd(2+), Pb(2+), Cu(2+), Fe(3+) and Al3+ exhibited inhibitory effects on the enzyme in vitro. K(i) constants and IC(50) values for metal ions were determined by Lineweaver-Burk graphs and plotting activity % vs. [I]. IC(50) values of Pb(2+), Hg(2+), Cu(2+), Cd(2+), Fe(3+) and Al(3+) were 0.011, 0.020, 0.0252, 0.0373, 0.209 and 0.229 mM, and the Ki constants 0.0254+/-0.0027, 0.0378+/-0.0043, 0.0409+/-0.0048, 0.0558+/-0.0083, 0.403+/-0.043 and 1.137+/-0.2 mM, respectively. While Pb(2+), Hg(2+), Cd(2+) and Fe(3+) showed competitive inhibition, others displayed noncompetitive inhibition.
Coban
T Abdulkadir
TA
Erzincan University, Department of Chemistry, Erzincan, Turkey. coban.1@osu.edu
Senturk
Murat
M
Ciftci
Mehmet
M
Kufrevioglu
O Irfan
OI
D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000201:enzymology*; D005980:Glutathione Reductase / Q000037:antagonists & inhibitors* / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D020128:Inhibitory Concentration 50; D007700:Kinetics; D008670:Metals / Q000494:pharmacology*
D008670:Metals; D005980:Glutathione Reductase