American Society of Hirudotherapy

Bdellin B3

Kazal-type proteinase inhibitor targeting trypsin and plasmin — modulates inflammatory cascade.

Preclinical / mechanisticLast updated: 2026-05-26 · Reviewed by ASH Editorial Board
Molecular weight of Bdellin B3 compared with other characterized leech-derived compoundsHementerin80 kDaHementin80 kDaHementin-Like Protein (HLP-1)80 kDaLeech Collagenase70 kDaHaemadipsa yanyuanensis Progr…70 kDaLeech Apyrase67 kDaCalin65 kDaHyaluronidase60 kDaAntithrombin III binding prot…58 kDaCollagenolytic Fibrinolysin55 kDaLeech Thrombospondin-Like Pro…50 kDaBdellin B35 kDa
Molecular weight (kilodaltons) of Bdellin B3 (highlighted) alongside other characterized leech salivary compounds. Smaller proteins/peptides generally diffuse and act faster.

Mechanistic Evidence Box

Preclinical / mechanistic
Page type
Compound profile
Evidence type
Kazal-type proteinase inhibitor targeting trypsin and plasmin — modulates inflammatory cascade.
Evidence level
In vitro
Drug vs leech
Purified natural compound

Clinical translation limit

Bdellin B3's in vitro inhibition of trypsin and plasmin does not establish clinical efficacy. No FDA-approved derivative exists. Mechanism is preclinical/biochemical only.

Molecular Profile

Category
Proteinase Inhibitor
Evidence tier
Preclinical
Molecular weight
5,000 Da
Source species
Hirudo medicinalis
Discovered
1986 · Fink et al.
Bdellin B3 molecular structure

Biological Targets

  • → trypsin
  • → plasmin

Key Citations

  1. Fink E et al. (1986), Biol Chem Hoppe-Seyler

External Resources

    Related Proteinase Inhibitor Compounds

    Hirustasin

    Serine proteinase inhibitor targeting tissue kallikrein — anti-inflammatory pathway.

    Eglin C

    Potent inhibitor of human leukocyte elastase and cathepsin G — anti-inflammatory protein widely used as research tool.

    LDTI (Leech-Derived Tryptase Inhibitor)

    Selective inhibitor of human mast cell tryptase — anti-inflammatory pathway.

    LCI (Leech Carboxypeptidase Inhibitor)

    Inhibitor of TAFI (thrombin-activatable fibrinolysis inhibitor) — synergizes with hirudin's anticoagulant action.

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