RELATIONSHIP BETWEEN THE MYOFIBRILLAR PROTEIN GEL STRENGTHENING EFFECT AND THE COMPOSITION OF SARCOPLASMIC PROTEINS FROM PACIFIC MACKEREL

To determine which protein bands appeared in SDS-polyacrylamide gel el ectrophoresis (PAGE) patterns of sarcoplasmic proteins (Sp-P) are resp onsible for the gel strengthening effect of Sp-P on the myofibrillar p rotein (Mf-P) gel, the relations between the jelly strength of Mf-P ge l added with each of three different sarcoplasmic fractions and the re lative amounts of protein bands in the SDS-PAGE pattern of each sarcop lasmic fraction were examined. The heat-coagulability of each sarcopla smic fraction was highly correlated with the jelly strength of each ge l. Relative amounts of 94, 64, and 40 kDa components in the SDS-PAGE p attern of each sarcoplasmic fraction also showed a good correlation wi th the jelly strength of gel. These results suggest that the high jell y strength of Sp-P added Mf-P gel is attributable to a large amount of heat-coagulable proteins, especially the 94, 64, and 40 kDa component s of Sp-P.