Biology:Venombin A
Venombin A (EC 3.4.21.74, alpha-fibrinogenase, habutobin, zinc metalloproteinase Cbfib1.1, zinc metalloproteinase Cbfib1.2, zinc metalloproteinase Cbfib2, ancrod) is an enzyme.[1][2][3][4][5] This enzyme catalyses the following chemical reaction
- Selective cleavage of Arg- bond in fibrinogen, to form fibrin, and release fibrinopeptide A. The specificity of further degradation of fibrinogen varies with species origin of the enzyme
This enzyme is a thrombin-like enzyme from venoms of snakes of the viper/rattlesnake group. Examples include ancrod and batroxobin, two serine proteases from snakes that have been used in medical preparations.[citation needed]
Applications
Venombin A enzymes are the sole representatives of the defibrinogenating agent class of drugs, which by its protease action removes fibrinogen from the circulation. They are thought to act as an antithrombotic by depletion of fibrinogen.[6] They are different from thrombin in that they only cleave fibrinogen alpha chain (those do cleave both chains are called venombin AB), which will end up only producing weak, urea-soluble microthrombi that is easily removed by plasmin.[7] Their benefit in acute ischaemic stroke is not supported by available evidence.[8]
Alternatively, batroxobin is also used as a topical hemostatic by its rapid local clot-expansion action.[9]
References
- ↑ Ancrod, the coagulating enzyme from Malayan pit viper (Agkistrodon rhodostoma) venom. Methods in Enzymology. 45. 1976. pp. 205–13. doi:10.1016/s0076-6879(76)45020-6.
- ↑ The coagulant enzyme from Bothrops atrox venom (batroxobin). Methods in Enzymology. 45. 1976. pp. 214–23. doi:10.1016/s0076-6879(76)45021-8.
- ↑ "Kallikrein-like activity of crotalase, a snake venom enzyme that clots fibrinogen". Proceedings of the National Academy of Sciences of the United States of America 79 (6): 1688–92. March 1982. doi:10.1073/pnas.79.6.1688. PMID 7043462.
- ↑ "Action of crotalase, an enzyme with thrombin-like and kallikrein-like specificities, on tripeptide nitroanilide derivatives". Thrombosis Research 40 (4): 555–61. November 1985. doi:10.1016/0049-3848(85)90292-0. PMID 2934864.
- ↑ "Organization of the gene for batroxobin, a thrombin-like snake venom enzyme. Homology with the trypsin/kallikrein gene family". The Journal of Biological Chemistry 263 (16): 7628–31. June 1988. doi:10.1016/S0021-9258(18)68544-8. PMID 3163691.
- ↑ Bell WR, Jr (1997). "Defibrinogenating enzymes.". Drugs 54 (Suppl 3): 18–30; discussion 30–1. doi:10.2165/00003495-199700543-00005. PMID 9360849.
- ↑ Kelton, JG; Smith, JW; Moffatt, D; Santos, A; Horsewood, P (1999). "The interaction of ancrod with human platelets.". Platelets 10 (1): 24–9. doi:10.1080/09537109976310. PMID 16801067.
- ↑ "Fibrinogen depleting agents for acute ischaemic stroke". The Cochrane Database of Systematic Reviews (3): CD000091. March 2012. doi:10.1002/14651858.CD000091.pub2. PMID 22419274.
- ↑ Vu, TT; Stafford, AR; Leslie, BA; Kim, PY; Fredenburgh, JC; Weitz, JI (7 June 2013). "Batroxobin binds fibrin with higher affinity and promotes clot expansion to a greater extent than thrombin.". The Journal of Biological Chemistry 288 (23): 16862–71. doi:10.1074/jbc.M113.464750. PMID 23612970.
External links
- Venombin+A at the US National Library of Medicine Medical Subject Headings (MeSH)
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