Lipid Peroxidation by Microsomal Fractions Isolated from Light and Dark Muscles of Herring (Clupea harengus)

Abstract

ABSTRACTEnzymic lipid peroxidation by light and dark muscle microsomes of herring (Clupea harengus) required ATP or ADP, NADH and Fe. NADPH could not effectively replace NADH. Inhibition was observed at high concentrations of ADP and NADH but not Fe. The optimal pH for the reaction of both types of microsomes was between 6 and 7. The average peroxidation rate was 362 and 1143 nmoles MDA per mg protein per hr at 6°C for the light and dark muscle microsomes, respectively. The energy of activation for the light and dark muscle microsomes was similar. The light muscle microsomes lost activity faster than the dark muscle microsomes when exposed to 35°C. Ferrous ion stimulated enzymic lipid peroxidation of light and dark muscle microsomes over that observed with ferric ion.