Glutathione peroxidase of calf trabecular meshwork.

Glutathione peroxidase was extracted from calf trabecular meshwork. The kinetics of this enzyme were examined, varying the substrates hydrogen peroxide (H2O2), tert- butylhydroperoxide ( tBHP ), and glutathione. The activity of the enzyme in nonpurified homogenates was 596 nmole H2O2 reduced/min/gm wet weight and 680 nmole tBHP reduced/min/gm wet weight (27-28 nmole peroxide reduced/min/mg protein). The apparent Michaelis--Menten constants for H2O2, tBHP , and GSH were 0.012, 0.102, and 2.89 mM, respectively. These data, together with published levels of glutathione in trabecular meshwork, suggest that the trabecular endothelial cell actively detoxifies H2O2.