Eglins b/c
Cysteine-free serine Protease-Inhibitoren with anti-inflammatory and neurotrophic properties
Zuletzt aktualisiert: June 18, 2026
Mechanismus-Haftungsausschluss
Eglins b and c are compact serine Protease-Inhibitoren originally isolated from Hirudo medicinalis Speicheldrüsensekret. At 8,073 Da (eglin b) and 8,099 Da (eglin c), they differ by a single Aminosäure substitution at position 35 (His in eglin b, Tyr in eglin c). With 70 Aminosäuren and no cysteine residues, eglins are uniquely devoid of disulfide bonds among leech Proteinase inhibitors — a feature that contributes to exceptional thermal and acid stability.
Structural Characteristics
Kartoffel-Inhibitor-I-Familie
Eglins belong to the potato inhibitor I (PI-1) superfamily, sharing structural homology with barley chymotrypsin inhibitor CI-2. This plant-origin fold in an animal Protease-Inhibitor suggests antik evolutionary convergence. The absence of disulfide bonds renders eglins resistant to reducing environments and simplifies recombinant production.
Einzelreste-Unterschied
Eglin b (His35) and eglin c (Tyr35) are otherwise identisch in sequence and exhibit overlapping but non-identisch inhibitory profiles. Eglin c wurde more extensively characterized aufgrund its early successful expression in E. coli (Rink et al., 1984) — eine der first leech Proteine produced recombinantly.
Inhibitionsprofil
| Zielprotease | Ki | Bedeutung |
|---|---|---|
| Neutrophile Elastase | 2 × 10⁻¹⁰ M | Sub-nanomolar; blockiert Gewebezerstörung |
| Cathepsin G | 2.8 × 10⁻¹⁰ M | Key neutrophil serine protease |
| Mastzell-Chymase | 4.45 × 10⁻⁸ M | Moderate; LDTI more potent for Mastzellen |
| α-Chymotrypsin | Nanomolarer Bereich | Breite Serinprotease-Aktivität |
| Subtilisin | Nanomolarer Bereich | Bakterielle Serinprotease |
Entzündungshemmende Bedeutung
The primary therapeutic interest in eglins centers on their ability to block neutrophil-mediated tissue destruction. During inflammatory responses, activated neutrophils release elastase and cathepsin G from azurophilic granules. Uncontrolled release of these proteases degrades extrazelluläre Matrix components (elastin, collagen, proteoglycans) and amplifies inflammatory cascades. Eglins inhibit sowohl Enzyme at sub-nanomolar concentrations, positioning them as potenziell modulators of Gewebeschaden in:
Rheumatoide Arthritis
Synoviale Neutrophilen-Infiltration
COPD
Elastase-getriebene Alveolar-Destruktion
ARDS
Neutrophile pulmonale Entzündung
Additional Biological Activities
Neurotrophe Aktivität
Eglin c demonstrates significant neurite outgrowth stimulation in chick embryo dorsal root Ganglien, with a 48.3% increase in explant area index (EAI) at a concentration of 0.1 ng/mL (Chapter 7). This places eglins among the biologically active SDS-Komponenten with dual anti-inflammatory and neurotrophic properties.
HCV-NS3-Proteinase-Hemmung
Martin et al. (1998) demonstrated that eglin c inhibits the hepatitis C virus NS3 serine Proteinase at nanomolar concentrations. Although not pursued therapeutically, this finding illustrates the broad-spectrum serine Protease-Inhibitory capacity of the eglin scaffold.
Piyavit Component
Eglins are constituent components of Piyavit, a pharmaceutical formulation derived from whole Blutegelextrakt. Their presence contributes to the immunomodulatory properties attributed to the formulation, including anti-inflammatory effects on neutrophil-mediated Gewebeschaden pathways.
Rekombinante Produktion
Rink et al. (1984) achieved die erste heterologous expression of eglin c in E. coli, producing active Protein in high yields. The absence of disulfide bonds and glycosylation sites makes eglins particularly amenable to bakteriell expression — a significant advantage for scale-up.
Verwandte Ressourcen
Bdellin A/B
Trypsin-, Plasmin- und Acrosin-Inhibitoren aus Blutegel-SDS.
Antiinflammatorische Mechanismen
SDS modulation of inflammatory pathways.
Verbindungsreferenz
Vollständige Datenbank bioaktiver SDS-Komponenten.
Compound Coverage Map
Eglins and the broader serine-protease-inhibitor family in the 107-compound catalogue.