Plasminogen

Function

Plasmin (PLN) is a serine protease which is involved in degradation of fibrin clots. PLN is released as the zymogen plasminogen (PLG) which is converted to the active PLN by a variety of enzymes. PLN cleavage produces angiostatin.

• Microplasmin induces posterior vitreous detachment from the retina (PVD)^[1].

Disease

PLN mutations are associated with ligneous conjunctivitis and other disorders which lead to development of pseudo membranes on mucosal surfaces^[2].

Structural highlights

PLN contains 7 domains which are: N-terminal, C-terminal serine protease catalytic domain and 5 kringle domains of ca. 80 residues. The kringle domain folds into a large loop containing 3 disulfide bonds, e.g. Kringle 4. The kringle domain is important in protein-protein interaction with blood coagulation factors.^[3].

• K ion coordination site. Water molecules are shown as red spheres.
• Cl ion coordination site I.
• Cl ion coordination site II.
• Cl ion coordination site III.
• Cl ion coordination site IV.

3D Structures of plasminogen

Plasminogen 3D structures