Identification and Screening of Novel Antimicrobial Peptides from Medicinal Leech via Heterologous Expression in E. coli
Basic science / preclinical published in Int J Mol Sci (2025)
Abstract
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.
Summary
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.
Why This Matters for Hirudotherapy
This study screened the Hirudo medicinalis genome for novel antimicrobial peptides using a high-throughput method based on recombinant expression of candidate AMP genes in E. coli, identifying three new peptides (LBrHM1, NrlHM1, NrlHM2) from the lumbricin and macin families that showed activity against E. coli, with two LBrHM1 fragments also active against Bacillus subtilis. This work is directly relevant to hirudotherapy and ASH because antimicrobial peptides are part of the medicinal leech's innate immune repertoire, and characterizing these bioactive molecules advances understanding of the leech secretome that underpins therapeutic leech applications. The N-terminal LBrHM1 fragment is notably unique among previously described AMPs. However, these are early-stage in vitro screening results, and extensive further research would be needed to assess therapeutic safety, in vivo efficacy, and clinical potential.
Citation
Identification and Screening of Novel Antimicrobial Peptides from Medicinal Leech via Heterologous Expression in E. coli.
Serebrennikova M et al. · International journal of molecular sciences, 2025
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