Partial purification and properties of glutathione peroxidase from carp hepatopancreas

1. Two glutathione peroxidases (GSH-Px), D1 and D2, were partially purified from the hepatopancreas of common carp Cyprinus carpio by ion-exchange, gel filtration, and hydrophobic chromatography. The enzymatic properties of those enzymes were examined. 2. The D1 and D2 differed in following enzymatic properties. The pH optima of D1 and D2 were 8.0 and 9.0, respectively. 3. When stored at pH 4.0 for 36 hr, D1 kept 70% of maximal activity while only 30% of that was shown in D2. 4. D1 and D2 lost activity by 50% when incubated at 55 degrees C and 65 degrees C for 10 min, respectively.