Studies on Plasminogen Activators. IV. An Enzyme Complex with Esterase Activity in Streptokinase-activated Human Plasma.

Interaction of streptokinase and human plasminogen. IV. Further gel electrophoretic studies on the combination of streptokinase with human plasminogen or human plasmin.

Streptokinase is shown to react with either human plasmin or human plasminogen to form an equimolar product which migrates in starch gel electrophoresis at pH 6.0 or 8.0 with a migration rate intermediate between the rates of migration of the two proteins. When streptokinase was present in molar excess in the reaction mixtures, the uncombined streptokinase displayed a migration rate at pH 6.0 (...

Mechanism of activation of human plasminogen by streptokinase. Presence of active center in streptokinase-plasminogen complex.

The role of proactivators for the streptokinase activation of human plasminogen was studied. It was found that plasmin, as well as plasminogen, can form activator complex with streptokinase. The relative importance of these two proactivators for the streptokinase activation of human plasminogen is discussed. The use of the active center-specific reagent, p-nitrophenylp-guanidinobenzoate (NPGB) ...

The streptokinase-human plasminogen activator complex. Composition and identity of a subcomponent with activator activity.

Reactions between purified plasminogen and streptokinase, labelled with (131)I and (125)I respectively, were investigated by polyacrylamide-gel discontinuous electrophoresis. A molecular complex consisting of both (131)I-labelled plasminogen and (125)I-labelled streptokinase migrated between plasminogen and streptokinase. This complex contained bovine plasminogen activator activity. The relativ...

Esterase activities in the zymogen moiety of the streptokinase-plasminogen complex.

Kinetic studies on novel plasminogen activators

The activation of plasminogen by two novel hybrid enzymes, constructed from the A-chain of plasmin and the B-chains of tissue-type plasminogen activator (t-PA) or urokinase, was compared with the activation by the parent enzymes. Basal kinetic constants for 'Lys-plasminogen' (human plasminogen with N-terminal lysine) and 'Glu-plasminogen' (human plasminogen with N-terminal glutamic acid) activa...