Decorsin & Ornatin
RGD-Peptid-Antagonisten des Thrombozyten-Integrins GP IIb/IIIa
Zuletzt aktualisiert: June 18, 2026
Mechanismus-Haftungsausschluss
Decorsin and ornatin are small RGD-containing peptides isolated from North American Blutegelart that function as potent competitive antagonists of the platelet integrin GP IIb/IIIa (αIIb/β3). This integrin is die am stärksten abundant receptor on the platelet surface (~80,000 copies per platelet) and serves as the final common pathway for Thrombozytenaggregation by binding fibrinogen to cross-link activated platelets.
Molekulare Eigenschaften
| Eigenschaft | Decorsin | Ornatin |
|---|---|---|
| Quelle | Macrobdella decora | Placobdella ornata |
| Molekulargewicht | 4.390 Da (39 Aminosäuren) | 5.590 Da (49 Aminosäuren) |
| Key motif | RGD (Arg-Gly-Asp) | RGD (Arg-Gly-Asp) |
| Ziel | GP IIb/IIIa (αIIb/β3) | GP IIb/IIIa (αIIb/β3) |
| Mechanismus | Kompetitiver Fibrinogen-Antagonist | Kompetitiver Fibrinogen-Antagonist |
Das RGD-Erkennungsmotiv
The Arg-Gly-Asp (RGD) tripeptide is the minimal recognition sequence for integrin receptors. First identified by Pierschbacher and Ruoslahti (1984) in fibronectin, RGD mediates cell adhesion across mehrere integrin-ligand pairs. In the hemostatic context, the RGD motif in fibrinogen engages GP IIb/IIIa on activated platelets, forming the cross-bridges that drive Thrombozytenaggregation. Decorsin and ornatin exploit this recognition system by presenting an RGD motif in a conformationally constrained peptide scaffold that competes with fibrinogen for integrin binding.
Pharmakologischer Kontext
Eptifibatide (Integrilin)
FDA-zugelassenen 1998. Cyclic heptapeptide derived from the disintegrin barbourin (Sistrurus miliarius barbouri, pygmy rattlesnake). Contains KGD motif (Lys-Gly-Asp) rather than RGD, providing GP IIb/IIIa selectivity. Used in acute coronary syndromes and percutaneous coronary intervention.
Tirofiban (Aggrastat)
FDA-zugelassenen 1998. Non-peptide tyrosine derivative designed as an RGD-mimetic. Small molecule GP IIb/IIIa antagonist used in acute coronary syndromes. Demonstrates the pharmacological principle validated by decorsin/ornatin research.
Although decorsin and ornatin themselves did not advance to klinisch development, they contributed significantly to the structural understanding of RGD-integrin interactions and informed the design of clinically successful GP IIb/IIIa antagonists.
Triple Antiplatelet Strategy of SGS
Three Independent Antiplatelet Mechanisms
Adhäsion
Thrombozyten-Kollagen-Interaktion
CalinVerankerung
vWF-mediated platelet capture
SaratinAggregation
GP IIb/IIIa-Fibrinogen-Bindung
Decorsin / OrnatinSDS simultaneously blocks all three steps of platelet-mediated primary hemostasis — a strategy no single pharmaceutical agent replicates.
Verwandte Ressourcen
Verbindungsreferenz
Vollständige Datenbank bioaktiver SDS-Komponenten.
Faktor-Xa-Inhibitoren
Antikoagulantien der Antistasin-Familie aus Blutegel-SDS.
Hämostase & Gerinnung
Multi-Target-Antikoagulations-Biologie.
Compound Coverage Map
RGD-motif antiplatelet compounds and the wider 107-entry leech compound catalogue.