Fast-acting plasmin inhibitor in human plasma
D Collen and B Wiman
The fast-acting and physiologically most important inhibitor of plasmin in
human plasma is a recently discovered and purified alpha 2- glycoprotein
with a molecular weight of 65,000-70,000 daltons occurring at a
concentration of 1 muM. The inhibitor rapidly forms a completely inactive
1:1 stoichometric complex with plasmin through reaction with the B chain
(light chain) of the enzyme, which contains the active center. It also
reacts with trypsin and very slowly with urokinase and with some other
enzymes in purified systems, but its role in vivo as an inhibitor of
proteases other than plasmin seems negligible. Antiplasmin is the only
plasma protein that can inhibit the fibrinolysis associated with
transformed or malignant cells. The plasmin-antiplasmin complex contains
neoantigenic structures not present in the parent molecules that may form
the basis of immunochemical methods for detecting activation of the
fibrinolvtic system in blood.
Volume 51,
Issue 4,
pp. 563-569,
04/01/1978
Copyright © 1978 by The American Society of Hematology
