Streptokinase catalyzes hydrolysis of amide linkages. Forms a 1:1 complex with plasminogen which is then converted to streptokinase-plasmin. Both streptokinase-plasminogen and streptokinase-plasmin complexes can activate plasminogen. As a result of its interaction with human or rabbit plasminogen, streptokinase undergoes specific fragmentation.

• Enzyme Commission Number: E.C. 3.4.99.0
• Soluble in water

It is commonly used as a thrombolytic agent in the therapy of ischemic stroke. This therapy carries the important risk of intracerebral hemorrhage. It is also used in the treatment of complicated parapneumonic effusions and empyema.

Unit definition: One unit is defined as the amount of enzyme that will liquefy a standard clot of fibrinogen, plasminogen and thrombin in 10 minutes at 37 °C and pH 7.