What is the Difference Between Streptokinase and Urokinase

The key difference between streptokinase and urokinase is that streptokinase is a fibrinolytic agent that is isolated from beta haemolytic Streptococcus bacteria, while urokinase is a fibrinolytic agent that is isolated from human urine.

The thrombosis process occurs when blood clots block veins and arteries. The general symptoms of this condition include pain and swelling in one leg, chest pain, and numbness on one side of the body. Complications that are associated with thrombosis include life-threatening conditions like stroke or heart attacks. Fibrinolytic agents are medicines that prevent clots by breaking down the thrombus. Streptokinase and urokinase are two common fibrinolytic agents.

CONTENTS

1. Overview and Key Difference
2. What is Streptokinase
3. What is Urokinase
4. Similarities – Streptokinase and Urokinase
5. Streptokinase vs Urokinase in Tabular Form
6. Summary – Streptokinase vs Urokinase

What is Streptokinase?

Streptokinase is a bacterial protein with a molecular weight of 47000 Da. It is usually isolated from beta haemolytic Streptococcus of Lancefield group c. It is a common fibrinolytic agent used to break down thrombus. It is a thrombolytic medication that is used to break down clots in life-threatening cases such as myocardial infarction, pulmonary embolism, and arterial thromboembolism. Normally, this medication is given through a vein as an injection. Streptokinase is not an enzyme, and its activation of plasminogen is indirect. This bacterial protein can form a stoichiometric complex with plasminogen, and this complex activates plasminogen to plasmin conversion.

Streptokinase complex with human plasminogen can hydrolytically activate other unbound plasminogen by activating through bond cleavage to produce respective plasmin. Moreover, there are three domains in streptokinase known as α, β, and γ. These domains collectively bind with plasminogen and activate it. Later, plasmin breaks down fibrin, the major constituent of blood clots, thereby dissolving the clot. Streptokinase was first discovered in 1933 from beta haemolytic Streptococcus. The side effects of this medicine include nausea, bleeding, low blood pressure, and allergic reactions. The second time usage of this medicine is not recommended. Furthermore, no harm has been found with usage in pregnancy. It is also on the World Health Organization’s list of essential medicines. However, it is no longer commercially available in the United States.

What is Urokinase?

Urokinase is a fibrinolytic agent that is isolated from human urine. It is also known as a urokinase plasminogen activator. This is a serine protease. It was discovered in 1947 by McFarlane and Pilling. This enzyme is also found in the blood and extracellular matrix of many tissues. PLAU is the gene coding this serine protease.

Urokinase directly converts plasminogen to plasmin by the specific cleavage of an arginine-valine bond in plasminogen. Furthermore, elevated levels of urokinase and other components of the plasminogen activation system are found to be correlated with tumor progression. Thus, it is believed that the degradation of tissues following plasminogen activation facilitates tissue invasion, which contributes to tumor metastasis. Moreover, it is directly administrated to the site of the clot. The side effects of this drug include bleeding gums, coughing up blood, headaches, nose bleeds, difficulty with breathing, paralysis, vaginal bleeding, red tools, dark brown urine, fast heartbeat, skin itching, wheezing, etc.

What are the Similarities Between Streptokinase and Urokinase?

• Streptokinase and urokinase are two common fibrinolytic agents.
• Both are proteins made up of amino acids.
• These drugs break down fibrin in the thrombus.
• Both medicines have side effects.
• They can be used in serious complications such as stroke or heart attack due to thrombosis.

What is the Difference Between Streptokinase and Urokinase?

Streptokinase is a fibrinolytic agent isolated from beta haemolytic Streptococcus bacteria, while urokinase is a fibrinolytic agent isolated from human urine. Thus, this is the key difference between streptokinase and urokinase. Furthermore, streptokinase is a bacterial protein, while urokinase is a human serine protease enzyme.

The below infographic presents the differences between streptokinase and urokinase in tabular form for side by side comparison.

Summary – Streptokinase vs Urokinase

Streptokinase and urokinase are two common fibrinolytic agents used in thrombolytic therapy. Streptokinase is a bacterial protein isolated from beta haemolytic Streptococcus bacteria, while urokinase is a serine protease enzyme isolated from human urine. So, this is the key difference between streptokinase and urokinase.

Reference:

1. “Streptokinase Uses, Interactions, Mechanism of Action.” DrugBank.
2. “Urokinase.” An Overview | ScienceDirect Topics.

Image Courtesy:

1. “Protein PLAU PDB 1c5w” By Emw – Own work (CC BY-SA 3.0) via Commons Wikimedia