CHARACTERIZATION OF NATTOKINASE-DEGRADED PRODUCTS FROM HUMAN FIBRINOGEN OR CROSS-LINKED FIBRIN

When the fibrinolytic activity of nattokinase was measured using clot lysis assay and compared with that of plasmin, nattokinase had more than 4 to 5 times the activity of plasmin, The action of nattokinase on the cleavage of fibrin(ogen) was also investigated by use of SDS-PAGE and Western blot analysis with anti-fragment D antibody or with anti D-dimer antibody, On SDS-PAGE, under non-reducing conditions, 105 kDa fragment carrying antigenic sites for the binding of anti-D antibody appeared within 3 min on the cleavage of fibrinogen with nattokinase under the conditions employed, Moreover, 175 and 110 kDa fragments appeared within 5 min on the cleavage of cross-linked fibrin by nattokinase, Since anti D-dimer antibody reacted with both fragments, the fragments may be derived from D-dimer remnants, When the proteolytic fragments of fibrin(ogen) were compared with those of plasmin at the same molarity of nattokinase, the similar fragments were obtained from the process of cleavage of fibrin(ogen), The cleavage of fibrinogen by nattokinase was 3 times less efficient than by plasmin as measured from kcat/Km, However, the cleavage of cross-linked fibrin by nattokinase was 6 times more efficient than by plasmin, The results suggest that nattokinase is less sensitive on the cleavage of fibrinogen, but is more sensitive on the cleavage of cross-linked fibrin as compared to plasmin.