Reptilase
| Reptilase | ||
|---|---|---|
| Mass / length primary structure | 231 amino acids, 36 kilodaltons | |
| Identifier | ||
| External IDs | ||
| Drug information | ||
| ATC code | B02 BX03 | |
| Enzyme classification | ||
| EC, category | 3.4.21.74 , serine protease | |
| MEROPS | S01.176 | |
| Response type | Proteolysis | |
| Substrate | Arg - + - Xaa in fibrin | |
| Products | Fibrinopeptide A | |
| Occurrence | ||
| Homology family | Trypsin | |
Reptilase , as batroxobin (BX) or Defibrase called, is from the venom of the family of American Terciopelos belonging snakes Bothrops atrox and Bothrops jararaca isolated enzyme . From a biochemical point of view it is a as a species- classified version of Venombin A serine proteinase . It influences in vertebrates the blood coagulation by promoting the cleavage of fibrinogen to fibrin and fibrinopeptide A. reptilase thus acts similar to the body's enzyme thrombin , but via a different mechanism. It was first described in 1957 and belongs to a class of enzymes known as Snake Venom Thrombin-like Enzymes (SVTLE; thrombin-like enzymes from snake venom).
Medical application
Reptilase promotes in vitro (outside the body) by the reaction of fibrinogen to fibrin, which blood coagulation and in the field of laboratory medicine for the detection of coagulation disorders employed. For this purpose, after the addition of reptilase to a blood sample, the time until coagulation is measured and stated as the reptilase time. The reference range is between 15 and 23 seconds. Falling below the lower limit has no diagnostic relevance; values above the reference range indicate delayed coagulation. In contrast to the analog test with thrombin, the coagulation triggered by reptilase is not inhibited by heparin or hirudin , so that the reptilase time can also be determined in heparinized blood. In addition, differences between the reptilase time and the thrombin time indicate the presence of therapeutically used heparin and certain disorders of fibrinogen formation.
It has been known since 1968 that Reptilase has a moderate anticoagulant effect in vivo (in the living organism), in contrast to its effect in vitro. The reason for this is that reptilase unlike thrombin not the coagulation factor XIII activated, the cross-linking of the formed from fibrinogen fibrin monomers to fibrin causes. The fibrin formed by reptilase is therefore more easily degradable than the thrombi formed by thrombin. By converting fibrinogen to fibrin and its subsequent rapid enzymatic breakdown, reptilase thus leads to a fibrinogen deficiency in the bloodstream , known as defibrinogenesis or defibrinogenation, which restricts blood clotting. Corresponding preparations can therefore be used therapeutically, for example, for supplementary treatment in the dissolution of blood clots and for the prevention of thromboses and embolisms, and are commercially available as medicaments . However, its use is limited for reasons of cost and because of the greater effect of other substances.
literature
- HC Castro, RB Zingali, MG Albuquerque, M. Pujol-Luz, CR Rodrigues: Snake Venom Thrombin-like Enzymes: From Reptilase to Now. In: Cellular and Molecular Life Sciences. 61/2004. Birkhauser Verlag, pp. 843-856, PMID 15095007 .
- N. Marsh, V. Williams: Practical Applications of Snake Venom Toxins in Haemostasis. In: Toxicon . 45 (8 )/2005. Elsevier, pp. 1171-1181, PMID 15922782 .
- K. Fickenscher: Tests with Thrombin-Like Enzymes. In: L. Thomas (Ed.): Labor und Diagnose. Sixth edition. TH-Books, Frankfurt am Main 2007, ISBN 3-98-052155-9 , p. 848ff.
