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 th an 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 f ragment carrying antigenic sites for the binding of anti-D antibody ap peared within 3 min on the cleavage of fibrinogen with nattokinase und er the conditions employed, Moreover, 175 and 110 kDa fragments appear ed within 5 min on the cleavage of cross-linked fibrin by nattokinase, Since anti D-dimer antibody reacted with both fragments, the fragment s may be derived from D-dimer remnants, When the proteolytic fragments of fibrin(ogen) were compared with those of plasmin at the same molar ity of nattokinase, the similar fragments were obtained from the proce ss of cleavage of fibrin(ogen), The cleavage of fibrinogen by nattokin ase was 3 times less efficient than by plasmin as measured from kcat/K m, However, the cleavage of cross-linked fibrin by nattokinase was 6 t imes more efficient than by plasmin, The results suggest that nattokin ase is less sensitive on the cleavage of fibrinogen, but is more sensi tive on the cleavage of cross-linked fibrin as compared to plasmin.