American Society of Hirudotherapy

Synthesis, structure, and structure-activity relationships of divalent thrombin inhibitors containing an alpha-keto-amide transition-state mimetic

Research article published in Protein science (1996)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Research reportDrug DevelopmentKrishnan R et al. · Protein science, 1996

Abstract

A new class of divalent thrombin inhibitors is described that contains an alpha-keto-amide transition-state mimetic linking an active site binding group and a group that binds to the fibrinogen-binding exosite. The X-ray crystallographic structure of the most potent member of this new class, CVS995, shows many features in common with other divalent thrombin inhibitors and clearly defines the transition-state-like binding of the alpha-keto-amide group. The structure of the active site part of the inhibitor shows a network of water molecules connecting both the side-chain and backbone atoms of thrombin and the inhibitor. Direct peptide analogues of the new transition-state-containing divalent thrombin inhibitors were compared using in vitro assays of thrombin inhibition. There was no direct correlation between the binding constants of the peptides and their alpha-keto-amide counterparts. The most potent alpha-keto-amide inhibitor, CVS995, with a Ki = 1 pM, did not correspond to the most potent divalent peptide and contained a single amino acid deletion in the exosite binding region with respect to the equivalent region of the natural thrombin inhibitor hirudin. The interaction energies of the active site, transition state, and exosite binding regions of these new divalent thrombin inhibitors are not additive.

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

Publication typeJournal ArticleResearch Support, U.S. Gov't, P.H.S.
Indexed MeSH termsAmidesAmino Acid SequenceAntithrombinsBinding SitesBlood ProteinsComputer GraphicsCrystallography, X-RayHirudinsHydrogen BondingModels, MolecularMolecular Sequence DataPeptides

Summary

Synthesis, structure, and structure-activity relationships of divalent thrombin inhibitors containing an alpha-keto-amide transition-state mimetic.

Why This Matters for Hirudotherapy

The abstract describes a new class of divalent thrombin inhibitors containing an alpha-keto-amide transition-state mimetic, reporting the X-ray crystallographic structure of the most potent member (CVS995, Ki = 1 pM) and comparing direct peptide analogues in in vitro thrombin-inhibition assays. Hirudin is referenced only as a 'natural thrombin inhibitor' whose exosite-binding region differs by a single amino acid deletion in the most potent inhibitor. The connection to leeches or hirudotherapy is at best indirect: the abstract does not mention leeches, leech secretions, or hirudotherapy, and all compounds described are synthetic chemical mimetics rather than natural leech products.

Citation

Synthesis, structure, and structure-activity relationships of divalent thrombin inhibitors containing an alpha-keto-amide transition-state mimetic

Krishnan R et al. · Protein science, 1996

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

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