PURIFICATION, CHARACTERIZATION, AND UTILIZATION OF PIG PLASMA FACTOR-XIIIA

To investigate the properties of pig plasma factor XIII (a zymogen of factor XIIIa, EC 2.3.2.13, TGase) and consequently to utilize the pig blood, factor XIII was purified to electrophoretical homogeneity after DEAE-Sephacel chromatography. The molecular weights were 320 000 estimated by Sepharose CL-6B and 75 000 by SDS-PAGE, suggesting this zymogen contains four subunits with identical molecular weights of 75 000. This proenzyme was activated by thrombin and Ca2+. Accordingly, the purified proenzyme was identified as factor XIII. The optimal temperature for incorporating monodansylcadaverine to beta-substrate was 55-degrees-C. Factor XIIIa (activated factor XIII) was inhibited by N-ethylmaleimide, p-(chloromercuri)benzoate, and idoacetic acid in the presence of Ca2+. The rate constants for thermal denaturation (K(d)) at 55-degrees-C of factor XIII and XIIIa were 5.0 x 10(-5) and 0.6 x 10(-5) s-1, respectively. Factor XIIIa catalyzed the covalent cross-linking of myosin heavy chain. The addition of crude plasma factor XIII (including thrombin) substantially increased the gel strength of minced mackerel.