Levels of plasma cysteine and blood glatathione in patients with cardiovascular diseases

The aim of this study was to determine whether the levels of aminothiols such as glutathione [GSH], cysteine [Cys] and homocysteine [Hcys] were affected by various cardiovascular diseases [CVD] and the relation between these two thiols Cys and GSH. Blood samples from 62 patients with atherosclerosis and 34 CV diseased subjects were analyzed and matched with control subjects. In the CV patients, free plasma Cys was significantly high and blood GSH levels were normal. In patients with ATH, bound plasma Cys was 21% higher than in control subjects and in patients with other CV diseases, it was 14% higher. There were no differences related to the duration of the disease or the functional disability. The abnormal levels of plasma Cys occurred in both ATH and other CV diseases indicated that high levels of oxidized and bound Cys in CV patients create an oxidative state which may increase the incidence to vascular damage

Purification and characterization of glutathione peroxidase from camel liver cytosol

Glutathione peroxidase [GSH: H2O2 oxidoreductase, EC 1.11.1.9] was purified to homogeneity from camel liver cytosol by ammonium sulfate fractionation and chromatography on CM-Sephadex C-50, DEAE-Sephadex A-50, followed by Sephadex G-200 and Sephadex G-100. The purified enzyme was homogeneous as judged by SDS-PAGE. The molecular weight of the enzyme as determined by SDS-PAGE was 66 +/- 2 kDa and that by gel filtration was comparable, indicated that the enzyme protein was a single polypeptide. The enzyme selenium content was calculated to be 4.4 g atoms/mole enzyme protein. The basic and acidic amino acids represent 40% of the total protein content. Optimum pH was 8.4 using tris-HCl buffer at 37C. Optimum temperature was 55C and the Km values for both GSH and cumene-OOH were 0.8 and 1.6 mM, respectively. Cadmium ions [II] was found to be a potent inhibitor. The purified enzyme was stable for more than 2 months under frozen conditions in the presence of dithiothreitol [DTT]