American Society of Hirudotherapy

Critical role of W60d in thrombin allostery.

Research article published in Biophysical chemistry (1997)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Research reportDrug DevelopmentSalivary PharmacologyGuinto et al. · Biophysical chemistry, 1997

Abstract

Mutation of residue W60d of thrombin, located 17 A from the Na+ binding site, suppresses Na+ binding and the functional differences between the slow and fast forms. The molecular basis for the long-range effect of this mutation is provided by a conspicuous network of water molecules which connects the Na+ binding environment to the specificity sites S1 and S2 of the enzyme. The mutation appears to stabilize thrombin in a hybrid conformation that is overall similar to the slow form, but with the fibrinogen recognition site functioning as in the fast form. It also affects the switch in specificity from fibrinogen to protein C linked to the release Na+ and the fast-->slow conversion. Under physiological conditions of pH, temperature and NaCl concentration, the W60dS mutant behaves as an anticoagulant. It has a reduced activity toward fibrinogen by 22-fold, while the reduction of protein C activation in the presence of saturating concentrations of thrombomodulin is less than 2-fold. Even more remarkable is the cleavage of fibrin I monomer leading to release of fibrinopeptide B, which is reduced by more than 130-fold. This property is reminiscent of the snake venom ancrod, which only releases fibrinopeptide A, and adds substantially to the anticoagulant potency of the W60dS mutant. In fact, the clotting time in the presence of this mutant is prolonged more than 40-fold compared to the wild-type.

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'tResearch Support, U.S. Gov't, P.H.S.
Indexed MeSH termsAllosteric RegulationMutagenesis, Site-DirectedPeptide FragmentsProtein ConformationSodiumThrombin

Summary

Mutation of residue W60d of thrombin, located 17 A from the Na+ binding site, suppresses Na+ binding and the functional differences between the slow and fast forms. The molecular basis for the long-range effect of this mutation is provided by a conspicuous network of water molecules which connects...

Why This Matters for Hirudotherapy

The abstract reports that mutation of thrombin residue W60d, located 17 Å from the Na+ binding site, suppresses Na+ binding and stabilizes a hybrid conformation with markedly reduced fibrinogen cleavage (22-fold) and fibrinopeptide B release (>130-fold), a smaller reduction of protein C activation in the presence of thrombomodulin (less than 2-fold), and prolonged clotting time (>40-fold), yielding an anticoagulant thrombin variant. This is relevant to thrombin allostery and anticoagulant mechanisms. However, the abstract does not mention leeches, hirudin, hirudotherapy, or leech-derived compounds. Therefore, the findings offer no direct evidence for ASH's domain; any leech-related connection would be speculative and unsupported by the abstract.

Citation

Critical role of W60d in thrombin allostery.

Guinto et al. · Biophysical chemistry, 1997

Added to ASH library: May 28, 2026 · Site last updated: June 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.