Comparison of Reactivity of Transglutaminase to Various Fish Actomyosins.

Abstract

It was found that all fish muscles analyzed contained transglutaminase (TGase) in an activity range of 2.41-0.10unit/g of wet weight. White croaker muscle has the highest activity followed in descending order by carp, walleye pollack, chum salmon, atka mackerel, and rainbow trout The reactivity of carp TGase to various fish actomyosins was investigated in terms of the velocity of polymerization of myosin heavy chain using a medium containing 5mg/ml actomyosin 5mM CaCl2, 0.5M NaCl, and 0-0.05 unit carp TGase at pH 7.5 and 25°. The rates of polymeri zation were significantly different according to the source of actomyosin ranging from 13.5 to 0.1h-1 E unit-1. The highest value was obtained from the actomyosin of walleye pollack, followed by those of rainbow trout, chum salmon, atka mackerel white croaker, and carp. These results sug gest that the TGase-mediated cross-linking reaction of myosin heavy chain may be mainly regulated by the conformational factor of the substrate actomyosin, depending on the species of fish. The combined effects of both factors, TGase content and reactivity, provided new insight into the species-specific set gel-formability of fish muscle pastes. © 1993, The Japanese Society of Fisheries Science. All rights reserved.