Ecarin is an

metalloprotease A metalloproteinase, or metalloprotease, is any protease enzyme whose catalytic mechanism involves a metal. An example is ADAM12 which plays a significant role in the fusion of muscle cells during embryo development, in a process known as myoge ...

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

that is derived from the venom of the Indian saw-scaled viper, ''

Echis carinatus ''Echis carinatus'', known as the Sindh saw-scaled viper, saw-scaled viper,Mallow D, Ludwig D, Nilson G (2003). ''True Vipers: Natural History and Toxinology of Old World Vipers''. Malabar, Florida: Krieger Publishing Company. 359 pp. . Indian sa ...

'', It is the primary reagent in the

Ecarin clotting time Ecarin clotting time (ECT) is a laboratory test used to monitor anticoagulation during treatment with hirudin, an anticoagulant medication which was originally isolated from leech saliva. Ecarin, the primary reagent in this assay, is derived from ...

test. Ecarin is known to activate prothrombin, another protein that is a critical component of the blood clotting cascade.

Origin

The venom of the saw-scaled viper, Echis carinatus, causes bleeding and eventually death. The venom contains ecarin, which converts prothrombin to meizothrombin, a thrombin analog with increased esterase activity, and not to normal thrombin.

Clinical Use

Ecarin is a highly versatile drug compound used in blood clotting experiments and for monitoring and treating a range of diseases, including cancer, liver diseases, lupus, and cardiovascular disorders.

Testing

Ecarin-based assays are tests that have the prospect to be clinically helpful in detecting vitamin K deficiency and lupus

anticoagulant An anticoagulant, commonly known as a blood thinner, is a chemical substance that prevents or reduces the coagulation of blood, prolonging the clotting time. Some occur naturally in blood-eating animals, such as leeches and mosquitoes, which ...

. The Ecarin clotting time (ECT) is a test that is widely used for lupus anticoagulant testing in certain regions. Ecarin-based testing is used to monitor

dabigatran etexilate Dabigatran, sold under the brand name Pradaxa among others, is an anticoagulant used to treat and prevent blood clots and to prevent stroke in people with atrial fibrillation. It is commonly used to prevent blood clots following hip or knee r ...

, a

thrombin Prothrombin (coagulation factor II) is encoded in the human by the F2-gene. It is proteolytically cleaved during the clotting process by the prothrombinase enzyme complex to form thrombin. Thrombin (Factor IIa) (, fibrose, thrombase, throm ...

inhibitor, with both clot-based and chromogenic-based methods available. In 2015, it was reported that 30% of oral anticoagulants prescribed for Medicare patients in the United States were direct oral anticoagulants (DOACs), with dabigatran being a popular choice among cardiologists and internal medicine physicians. This is largely due to the drug's safety and efficacy. It has been shown to be effective in preventing stroke and systemic embolism, and has a lower risk of bleeding compared to warfarin. However, it is important to note that monitoring the effects of dabigatran can be challenging, as traditional coagulation tests such as the prothrombin time (PT) and activated partial thromboplastin time (aPTT) are not sensitive to the drug's effects. This is where Ecarin-based testing comes in, as it provides a more accurate measure of dabigatran's anticoagulant effect.

Research

Ecarin is a glycoprotein with unique metalloproteinase properties. It has a molecular weight of 56,000 and has been found to specifically activate only prothrombin due to its strict substrate specificity. To compare the covalent structures of Ecarin and RVV-X, researchers have determined the complete cDNA sequence and translated protein sequence of Ecarin.

References

{{Proteases Enzymes