PROTEOLYTIC DERIVATIVES OF PLASMINOGEN AS A FACTOR IN MALIGNANCY DEVELOPMENT

The structure of plasminogen (Plg) molecule, its specificity and sub-domain arrangement of its molecular interaction cites is described. The differences in the set of characteristics of an intact Plg as compared to its proteolytic derivatives suggest an important role of the latter. Their impact on the course of oncologic process is shown to be contradictory. On the one hand, cringle-containing fragments are efficient in blocking the sites of functionally meaningless Plg activation thus fostering the restoration of the offset activation-inhibition balance; on the other hand, cringle structures being deprived of the enzyme’s proteolytic portion prevent α2-antiplasmin-mediated inhibition while hydrolytic and activation activities are preserved further aggravating the above mentioned imbalance.