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J Thromb Thrombolysis (2007) 23:923 DOI 10.1007/s11239-006-9011-x
Streptokinasethe drug of choice for thrombolytic therapy
Adinarayana Kunamneni Thaer Taleb Abed Abdelghani Poluri Ellaiah
Published online: 17 November 2006 Springer Science+Business Media, LLC 2006
Abstract Thrombosis, the blockage of blood vessels with clots, can lead to acute myocardial infarction and ischemic stroke, both leading causes of death. Other than surgical interventions to remove or by pass the blockage, or the generation of collateral vessels to provide a new blood supply, the only treatment available is the administration of thrombolytic agents to dissolve the blood clot. This article describes a comprehensive review of streptokinase (SK). We discuss the biochemistry and molecular biology of SK, describing the mechanism of action, structures, conrmational properties, immunogenecity, chemical modication, and cloning and expression. The production and physico-chemical properties of this SK are also discussed. In this review, considering the properties and characteristics of SK that make it the drug of choice for thrombolytic therapy.
Keywords Streptokinase (SK) Plasminogen activators Fibrinolysis Thrombolytic therapy
Introduction
In recent years, thrombolytic therapy with brinolytic (thrombolytic) agents has revolutionized the treatment
of diverse circulatory disorders such as pulmonary embolism, deep-vein thrombosis and myocardial infarction [1]. These circulatory disorders are increasingly becoming the leading causes of mortality in modern societies worldwide. Thrombolytic agents have the unique ability to activate the components intrinsic to the brinolytic system, resulting in the degradation of blood clots, which restores blood ow through the occluded vessels [2, 3].
The brinolytic agents commonly used in thrombolytic therapy are streptokinase (SK), urokinase (UK) and tissue type plasminogen activator (TPA). These agents are commonly referred to as plasminogen activators, since their mode of action is through the conversion of the enzymatically inert plasminogen (PG) of the brinolytic system to an active protease, plasmin (PN), that dissolves the brin clots and solubilises degradation products, which can be removed by the phagocytes.
This helps to restore blood ow through the occluded vessel. Unlike UK and TPA, which themselves proteases, SK possesses no enzymatic activity of its own. Rather, it acquires the highly specic PG activating property indirectly, by rst forming a high-afnity 1:1 stoichiometric complex with PG or PN. The resultant activator complex is a highly specic protease, which converts other PG molecules to proteolytically active PN through...