American Society of Hirudotherapy

Phospho-Hirudin (pY63 variant)

Synthetic phosphotyrosine-63 hirudin analog with higher thrombin affinity than native sulfo-hirudin — Volkova 2023 steered-MD + in vitro plasma assay.

Preclinical / mechanisticLast updated: 2026-05-27 · Reviewed by ASH Editorial Board
Molecular weight of Phospho-Hirudin (pY63 variant) 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 kDaPhospho-Hirudin (pY63 variant)7 kDa
Molecular weight (kilodaltons) of Phospho-Hirudin (pY63 variant) (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
Synthetic phosphotyrosine-63 hirudin analog with higher thrombin affinity than native sulfo-hirudin — Volkova 2023 steered-MD + in vitro plasma assay.
Evidence level
In vitro
Drug vs leech
Synthetic analog
Safety domains
Bleeding

Clinical translation limit

Phospho-hirudin's superior in silico binding and in vitro plasma activity do NOT establish clinical efficacy. No FDA-approved phospho-hirudin derivative exists; clinical hirudin analogs (lepirudin, desirudin, bivalirudin) use different post-translational modifications.

Molecular Profile

Category
Anticoagulant
Evidence tier
Preclinical
Molecular weight
7,000 Da
Source species
Hirudo medicinalis (sequence template)
Discovered
2023 · Volkova A, Semenyuk P
Phospho-Hirudin (pY63 variant) molecular structure

Biological Targets

  • thrombin (Factor IIa); Tyr63 phosphate enhances binding to exosite I

Key Citations

  1. Volkova A, Semenyuk P (2023), Proteins · PMID 37860993

External Resources

    Related Anticoagulant 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.