Plasminogen (Mini-plasminogen fragment) (Mini-PLG)

Mini-plasminogen is a truncated derivative of the human zymogen plasminogen, specifically comprising the fifth kringle domain (K5) and the C-terminal serine protease catalytic domain (UniProt: P00747). It is typically generated through the limited proteolysis of native Glu-plasminogen or Lys-plasminogen by enzymes such as elastase, which removes the first four kringle domains (PubMed: 621643). This structural modification results in the loss of high-affinity lysine-binding sites (LBS), which significantly alters its affinity for fibrin and its susceptibility to inhibition by alpha-2-antiplasmin compared to the full-length molecule (Journal of Biological Chemistry: 253(11):3831-6). Despite these changes, mini-plasminogen can be efficiently converted into the active enzyme mini-plasmin by various plasminogen activators, including urokinase and streptokinase (PubMed: 3894348). Once activated, mini-plasmin retains its catalytic efficiency in cleaving fibrin, although its localization and inhibition profiles differ from those of full-length plasmin. Research into mini-plasminogen has focused on its potential as a thrombolytic agent, as its smaller size may allow for better penetration into dense fibrin clots. It serves as a critical model for understanding the domain-specific functions of the plasminogen system and remains a target of interest for developing specialized fibrinolytic therapies for cardiovascular diseases.

Other names

Mini-plasminogenK5-PD fragmentVal442-plasminogenMini-PLG

Activation by plasminogen activators into the active serine protease mini-plasmin, which enzymatically degrades fibrin to dissolve blood clots.