American Society of Hirudotherapy

The hirudin-like factors HLF3 and HLF4-hidden hirudins of European medicinal leeches

Research article published in Parasitology research (2020)

Last Updated: March 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Drug DevelopmentGenomics & ProteomicsMüller C et al. · Parasitology research, 2020

Abstract

The hirudin-like factors 3 (HLF3) and 4 (HLF4) belong to a new class of leech-derived factors and are present in specimens of the three European medicinal leeches, Hirudo medicinalis, Hirudo verbana, and Hirudo orientalis, respectively. Here we describe the functional analysis of natural and synthetic variants of HLF3 and HLF4. Whereas the natural variants display only very low or no detectable anti-coagulatory activities, modifications within the N-termini in combination with an exchange of the central globular domain have the potency to greatly enhance the inhibitory effects of respective HLF3 and HLF4 variants on blood coagulation. Our results support previous observations on the crucial importance of all parts (both the N- and C-termini as well as the central globular domains) of hirudin and HLF molecules for thrombin inhibition.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal Article
Indexed MeSH termsAmino Acid SequenceAnimalsBlood CoagulationHirudinsHirudo medicinalisLeechesProtein DomainsRecombinant ProteinsStructure-Activity RelationshipThrombin

Summary

The hirudin-like factors 3 (HLF3) and 4 (HLF4) belong to a new class of leech-derived factors and are present in specimens of the three European medicinal leeches, Hirudo medicinalis, Hirudo verbana, and Hirudo orientalis, respectively.

Why This Matters for Hirudotherapy

Relevant to the development and clinical application of leech-derived pharmaceutical compounds.

Citation

The hirudin-like factors HLF3 and HLF4-hidden hirudins of European medicinal leeches.

Müller C et al. · Parasitology research, 2020

Added to ASH library: March 18, 2026 · Site last updated: March 18, 2026

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.

The hirudin-like factors HLF3 and HLF4-hidden hirudins of European medicinal leeches | ASH