Se-dependent GSH-peroxidase isolated from black sea bass (Centropristis striata)

1. Black sea bass were injected i.p. with Na 2 SeO 3 (Se-75). A GSH-dependent peroxidase was extracted from the liver via differential centrifugation and gel filtration chromatography. 2. Sea bass liver GSH-peroxidase eluted coincidently with Se-75 and was estimated to have a molecular weight of 72,000. 3. The nature of the selenium-protein bond in the peroxidase was investigated by dialysis vs sodium selenite, glutathione (a sulfhydryl reagent) and alkali. It was concluded that the Se-75 was associated with the peroxidase through a non-sulfhydryl linkage likely to be a C—Se bond. 4. This study confirms that Se is found in a GSH-peroxidase fraction isolated from black sea bass and suggests that Se may play an important role in marine fish.