Partial purification and characterization of six transglutaminases from ordinary muscles of various fishes and marine invertebrates.

Six transglutaminases were prepared from ordinary muscles of scallop (Patinopecten yessoensis), botan shrimp (Pandalus nipponensis), squid (Todarodes pacificus), carp (Cyprinus carpio), rainbow trout (Oncorhynchus mykiss), and atka mackerel (Pleurogrammus azonus), and their physicochemical and enzymatic properties were compared with each other. The Km value of carp transglutaminase for monodansyl cadaverine, a kind of primary amines, was 0.33 mM, while the other enzymes had Km values of 0.01-0.03 mM. The Km, values for succinylated casein of scallop, botan shrimp, squid, carp, rainbow trout, and atka mackerel enzymes were 1.2, 0.3, 1.8, 0.3, 0.2, and 0.1 mg/ml, respectively. In the presence of 0.5 M NaCl, the activities of scallop, botan shrimp, and squid transglutaminases were further enhanced about 11-, 2-, and 6-fold, respectively. There was no effect of NaCl on the activities of fish enzymes. These increment in the activities were dependent of NaCl concentrations and could be exhibited by using KCl instead of NaCl. To date there are no reports on types of transglutaminases whose activities are stimulated by salts. These findings suggest there exist a novel type of TGase in marine invertebrate muscles in which the osmotic pressure is isotonic to sea water.