Identification and Screening of Novel Antimicrobial Peptides from Medicinal Leech via Heterologous Expression in E. coli

The growing threat of infectious diseases requires novel therapeutics with different mechanisms of action. Antimicrobial peptides (AMPs), which are crucial for innate immunity, are a promising research area. The medicinal leech (Hirudo medicinalis) is a potential source of bioactive AMPs that are vital while interacting with microorganisms. This study aims to investigate the antimicrobial properties of peptides found in the H. medicinalis genome using a novel high-throughput screening method based on the expression of recombinant AMP genes in Escherichia coli. This approach enables the direct detection of AMP activity within cells, skipping the synthesis and purification steps, while allowing the simultaneous analysis of multiple peptides. The application of this method to the first identified candidate AMPs from H. medicinalis resulted in the discovery of three novel peptides: LBrHM1, NrlHM1 and NrlHM2. These peptides, which belong to the lumbricin and macin families, exhibit significant activity against E. coli. Two fragments of the new LBrHM1 homologue were synthesised and studied: a unique N-terminal fragment (residues 1-23) and a fragment (residues 27-55) coinciding with the active site of lumbricin I. Both fragments exhibited antimicrobial activity in a liquid medium against Bacillus subtilis. Notably, the N-terminal fragment lacks homologues among previously described AMPs.

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

High-throughput screening of candidate AMPs from the Hirudo medicinalis genome using recombinant expression in E. coli. Discovery of three novel AMPs (LBrHM1, NrlHM1, NrlHM2) from lumbricin and macin families, including a unique N-terminal fragment without prior homologues.

Leech-derived molecules this paper discusses, each with a full profile in the ASH compound registry:

Explore how this research connects to clinical practice

More peer-reviewed studies in Salivary Pharmacology.

• Novel Leech Antimicrobial Peptides — Hirunipins — Kumar et al. (2025)
• 434 Salivary Proteins — Integrated Proteomics of Hirudo medicinalis — Liu et al. (2019)
• Medicinal Leech Genome Assembly — Anticoagulant Gene Catalog — Kvist et al. (2020)
• Effects of hirudotherapy on liver functions, lipid profile, and insulin sensitivity in rats with metabolic syndrome — Bilden A et al. (2026)
• [Research progress in hirudin fusion protein--review] — Zhang C et al. (2007)
• A unique proteolytic fragment of human fibrinogen containing the A alpha COOH-terminal domain of the native molecule — Kirschbaum NE, Budzynski AZ (1990)
• Updates on Use and Monitoring of Direct Thrombin Inhibitors — Navaei A et al. (2026)
• Production and functional characteristics of a novel hirudin variant with better anticoagulant activities than bivalirudin — Ge P et al. (2025)
• Traditional Chinese medicine in the treatment of diabetic kidney disease: the mechanisms of signaling pathways regulations — Li W et al. (2026)
• Prostaglandin E1 is an efficient molecular tool for forest leech blood sucking — Zheng F et al. (2021)

Browse all ASH-analysed research →