[Glutathione peroxidase activity of frog eye pigment epithelium].

A highly active glutathione peroxidase (80% of which is localized in the water-soluble fraction) was detected in frog eye pigment epithelium tissue. It was shown that more than 75% of the glutathione peroxidase activity of the pigment epithelium tissue is bound to the Se-dependent enzyme. The Km values for glutathione and tret-butyl hydroperoxide were determined. It was found that Se, being a constituent of the melanoprotein granules, is not coupled to glutathione peroxidase.