Effect of neutral salts on activity and stability of transglutaminase from scallop adductor muscle

A sodium chloride-stimulated transglutaminase (TGase) is widely distributed in the muscle of marine invertebrates. The TGase from the adductor muscle of scallop (Patinopecten yessoensis) was used to investigate the interaction between the enzyme and neutral salts. At various sodium chloride concentrations, the Michaelis constant values for the substrates, monodansyl cadaverine and succinylated casein, were constant. Enhancement in activity by the addition of sodium chloride occurred instantly and reversibly, suggesting small conformational changes of the TGase. This increased activity was also exhibited by other sodium salts with the following order of effectiveness: Cl- = Br- > I- = NO;. TGase was inactivated when pre-incubated with sodium chloride in the absence of both substrates. Inactivation rates increased with increase in sodium chloride concentration and temperature. It was suggested that enhanced muscle TGase activity is induced by the contact with seawater or body fluids, and may be involved in wound healing. (C) 1999 Elsevier Science Inc. All rights reserved.