Purification and Characterization of Transglutaminase from Walleye Pollack Liver

Transglutaminase (TGase, EC 2. 3. 2. 13) from walleye pollack Theragra Chalcogramma liver was purified to electrophoretical homogeneity by Q-Sepharose and S-Sepharose chromatographies. The purified enzyme of 0.34mg was obtained from 15g of liver tissue and 591-fold purification was achieved from the liver extract. The molecular weight was estimated to be 77 kDa by SDS-polyacrylamide gel electrophoresis. The optimum pH and temperature for monodansyl cadaverine incorporation to N, N'-dimethylated casein were 9.0 and 50°C, respectively. The purifiedenzyme required Ca2+ above 3mM for the maximum activity, and Sr2+ also fully activated the enzyme. The activity was inhibited by sulfhydryl reagent, suggesting this enzyme was a thiol enzyme, the same as mammalian TGases. By this purified TGase, the gelation of myosin B solution was catalyzed, possibly through the polymerization of myosin heavy chains.