American Society of Hirudotherapy

Structure of the leech protein saratin and characterization of its binding to collagen

Research article published in Journal of molecular biology (2008)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Drug DevelopmentGronwald W et al. · Journal of molecular biology, 2008

Abstract

The leech protein Saratin from Hirudo medicinalis prevents thrombocyte aggregation by interfering with the first binding step of the thrombocytes to collagen by binding to collagen. We solved the three-dimensional structure of the leech protein Saratin in solution and identified its collagen binding site by NMR titration experiments. The NMR structure of Saratin consists of one alpha-helix and a five-stranded beta-sheet arranged in the topology betabetaalphabetabetabeta. The C-terminal region, of about 20 amino acids in length, adopts no regular structure. NMR titration experiments with collagen peptides show that the collagen interaction of Saratin takes place in a kind of notch that is formed by the end of the alpha-helix and the beta-sheet. NMR data-driven docking experiments to collagen model peptides were used to elucidate the putative binding mode of Saratin and collagen. Mainly, parts of the first and the end of the fifth beta-strand, the loop connecting the alpha-helix and the third beta-strand, and a short part of the loop connecting the fourth and fifth beta-strand participate in binding.

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

Publication typeJournal ArticleResearch Support, Non-U.S. Gov't
Indexed MeSH termsAmino Acid SequenceAnimalsCollagenLeechesMagnetic Resonance SpectroscopyModels, MolecularMolecular Sequence DataPeptidesProtein BindingProtein Structure, SecondaryProtein Structure, TertiarySalivary Proteins and Peptides

Summary

The leech protein Saratin from Hirudo medicinalis prevents thrombocyte aggregation by interfering with the first binding step of the thrombocytes to collagen by binding to collagen.

Why This Matters for Hirudotherapy

This study solved the three-dimensional NMR solution structure of Saratin, a leech-derived protein from Hirudo medicinalis that prevents thrombocyte aggregation by binding collagen, and characterized its collagen-binding site. The structure comprises one alpha-helix and a five-stranded beta-sheet, with NMR titration and docking experiments identifying a binding notch formed by the end of the alpha-helix and the beta-sheet involving specific strands and loops. This is directly relevant to ASH's domain as it elucidates the structural basis of a leech secretome protein's antithrombotic mechanism at the molecular level. However, this is a structural/biochemical study using model collagen peptides with no in-vivo or clinical data, so therapeutic implications remain untested.

Citation

Structure of the leech protein saratin and characterization of its binding to collagen

Gronwald W et al. · Journal of molecular biology, 2008

Added to ASH library: May 27, 2026 · Site last updated: June 18, 2026

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