Plasmin converts pro-form of group I phospholipase A2 into receptor binding, active forms.

Treatment of zymogen of pancreatic-type group I phospholipase A2 (PLA2-I) by plasmin, a fibrinolytic enzyme, increases PLA2 activity as well as receptor binding activity in a dose- and time-dependent manner. Separation of plasmin-treated pro-PLA2-I by HPLC and amino acid sequence analysis of the products revealed that, in addition to an authentic mature PLA2-I produced by trypsin, plasmin produced active products which had been modified in the C-terminal region. Thus, PLA2-I may be involved in physiologic processes which accompany the formation of plasmin.