The key difference between streptokinase and tPA is that streptokinase is a bacterial protein used as a thrombolytic medication while tPA (tissue plasminogen activator) is a recombinant mammalian protein used as a thrombolytic medication.

Thrombolysis is the process that breaks down blood clots formed in the blood vessels. It is also known as fibrinolytic therapy. Thrombolytic medications are medications used for thrombolysis. ST-elevation myocardial infarction, stroke, massive pulmonary embolism, severe deep vein thrombosis, acute limb ischemia, and clotted hemothorax are several types of diseases that need thrombolysis. Thrombolytic drugs are biologics. They can be developed either from Streptococcus species or by using recombinant biotechnology. Streptokinase and tPA are two thrombolytic drugs.

CONTENTS

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

What is Streptokinase?

Streptokinase is a thrombolytic medication. It is a bacterial protein derived from the Streptococcus species and was discovered in 1933 from beta-hemolytic streptococci. As a medication, it is useful in breaking blood clots developed in cases of myocardial infarction, pulmonary embolism, and arterial thromboembolism. It is available as an injection and can be injected into a vein.

Figure 01: Streptococcus

Streptokinase is fibrinolytic. Complexes of streptokinase, together with human plasminogen, can hydrolytically activate unbound plasminogen by activating bond cleavage to produce plasmin. There are three domains (α, β, γ) in streptokinase that can bind with plasminogen. The produced plasmin breaks fibrin, which is the major constituent of blood thrombi (blood clots). An overdose of streptokinase can be treated with aminocaproic acid. The possible side effects of this medication include nausea, bleeding, low blood pressure, and allergic reactions. A second-time use in a person’s lifetime is not usually recommended. No harm has been found with the use of this drug during pregnancy. Furthermore, it is also on the list of essential medicines in the World Health Organization. However, streptokinase is no longer commercially available in the United States.

What is tPA?

Tissue plasminogen activator (tPA) is a recombinant mammalian protein developed to use as a thrombolytic medication. It is a protein involved in the breakdown of blood clots. tPA is a serine protease normally found on endothelial cells. The endothelial cells are the cells that line the blood vessels. tPA is an enzyme that catalyzes the conversion of plasminogen to plasmin. Human tPA has a molecular weight of 70 kDa approximately. The tissue plasminogen activator is encoded by the PLAT gene located on chromosome 8.

Figure 02: tPA

As a thrombolytic drug, tPA can be manufactured using recombinant biotechnology. tPA produced by recombinant technology are called recombinant tissue plasminogen activator (rtPA). rtPA was first produced by recombinant DNA techniques at Genentech in 1982. Alteplase, reteplase, and tenecteplase are multiple brand names of recombinant tPA currently sold. They are useful in clinical medicine to treat embolic or thrombotic stroke. The side effects of rtPA include nausea, vomiting, low blood pressure, dizziness, mild fever, and allergic reactions.

What are the Similarities Between Streptokinase and tPA?

• Streptokinase and tPA are two thrombolytic drugs.
• They are enzymatic proteins.
• Both drugs convert plasminogen to plasmin, thereby breaking fibrin in blood thrombi.
• These drugs are used in case of myocardial infarction, pulmonary embolism, and stroke.
• Both drugs are on the list of essential medicines in the World Health Organization.
• Overdose of both drugs can be treated with aminocaproic acid.

What is the Difference Between Streptokinase and tPA?

Streptokinase is a bacterial protein used as a thrombolytic medication, while tPA is a recombinant mammalian protein used as a thrombolytic medication. Thus, this is the key difference between streptokinase and tPA. Furthermore, the molecular weight of streptokinase is approximately 47 kDa, while the molecular weight of tPA is approximately 70 kDa.

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

Summary – Streptokinase vs tPA

Streptokinase and tPA are two thrombolytic medications. Streptokinase is a bacterial protein derived from the Streptococcus species. On the other hand, tPA (tissue plasminogen activator) is a recombinant mammalian protein. So, this is the summary of the difference between streptokinase and tPA.

Reference:

1. “Streptokinase.” An Overview | ScienceDirect Topics.
2. “Tissue Plasminogen Activator.” An Overview | ScienceDirect Topics.

Image Courtesy:

1. “Group A strep” By NIH Image Gallery (CC BY-NC 2.0) via Flickr
2. “Protein PLAT PDB 1a5h” By Emw – Own work (CC BY-SA 3.0) via Commons Wikimedia

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