American Society of Hirudotherapy

Cystatin-Hv

Recombinant cystatin / cysteine protease inhibitor from Haementeria vizottoi leech — Linhares 2021 potent CatL inhibitor (Ki 7.9 nM).

Preclinical / mechanisticLast updated: 2026-05-27 · Reviewed by ASH Editorial Board
Molecular weight of Cystatin-Hv 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 kDaCystatin-Hv11.5 kDa
Molecular weight (kilodaltons) of Cystatin-Hv (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
Recombinant cystatin / cysteine protease inhibitor from Haementeria vizottoi leech — Linhares 2021 potent CatL inhibitor (Ki 7.9 nM).
Evidence level
In vitro
Drug vs leech
Recombinant (genetically expressed)

Clinical translation limit

Cystatin-Hv's in vitro CatL inhibition does NOT establish clinical efficacy in cancer or cardiovascular disease where CatL is implicated. No FDA-approved derivative exists; Haementeria vizottoi is not the FDA-cleared K040187 medicinal leech species.

Molecular Profile

Category
Proteinase Inhibitor
Evidence tier
Preclinical
Molecular weight
11,500 Da
Source species
Haementeria vizottoi
Discovered
2021 · Linhares DC et al.
Cystatin-Hv molecular structure

Biological Targets

  • cathepsin L (lysosomal cysteine protease; Ki 7.9 nM)

Key Citations

  1. Linhares DC et al. (2021), Toxins (Basel) · PMID 34941695

External Resources

    Related Proteinase Inhibitor Compounds

    This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.