Abstract
Effects of the polar fraction contained in the autoxidized triglyceride of sardine oil on the K-ATPase activity and the cross-linking of myosin heavy chain (HC) of myofibrils (Mf) were investigated.
Purified triglyceride was allowed to autoxidize at 37°C, and the triglyceride oxidation products (TGOP) were prepared with different polar fraction contents. Decrease in the K-ATPase activity and the amount of remaining intact myosin HC upon incubation of Mf with TGOP were measured. Both changes correlated with the polar fraction content in the TGOP employed.
The polar fraction and unoxidized triglyceride were both isolated from the TGOP by thin-layer chromatography (TLC), and it was found that K-ATPase inactivation and cross-linking reaction were both brought about by only the polar fraction. Since the TGOP employed in this study contained practically no free fatty acids and aldehydes detectable on TLC, the oxidation of thiol groups of myosin and cross-linking of HC are attributed to the polar fraction in the TGOP.
