Kinetics of the inhibition of thrombin by hirudin

The dissociation constant for hirudin was determined by varying the concentration of hirudin in the presence of a fixed concentration of thrombin and tripeptidyl p-nitroanilide substrate. The estimate of the dissociation constant determined in this manner displayed a dependence on the concentration of substrate which suggested the existence of two binding sites at which the substrate was able to compete with hirudin. A high-affinity site could be correlated with the binding of the substrate at the active site, and the other site had an affinity for the substrate that was 2 orders of magnitude lower. Extrapolation to zero substrate concentration yielded a value of 20 fM for the dissociation constant of hirudin at an ionic strength of 0.125. The dissociation constant for hirudin was markedly dependent on the ionic strength of the assay; it increased 20-fold when the ionic strength was increased from 0.1 to 0.4. This increase in dissociation constant was accompanied by a decrease in the rate with which hirudin associated with thrombin. This rate could be measured with a conventional recording spectrophotometer at higher ionic strength and was found to be independent of the binding of substrate at the active site.

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

The dissociation constant for hirudin was determined by varying the concentration of hirudin in the presence of a fixed concentration of thrombin and tripeptidyl p-nitroanilide substrate.

Explore cómo esta investigación se conecta con la práctica clínica

More peer-reviewed studies in Desarrollo de fármacos.

• Novel Leech Antimicrobial Peptides — Hirunipins — Kumar et al. (2025)
• Medicinal Leech Genome Assembly — Anticoagulant Gene Catalog — Kvist et al. (2020)
• BRIGHT-4 Trial — Bivalirudin vs Heparin by BMI — BRIGHT-4 Investigators (2025)
• RE-LY Trial — Dabigatran vs Warfarin in Atrial Fibrillation — Connolly SJ et al. (2009)
• Hirudin Disrupts Breast Cancer CTC Clusters — Anti-Metastatic Potential — Research team (2025) (2025)
• Novel CRA Protein from Hirudo medicinalis — Complement Regulation — Research team (2025) (2025)
• Hirunipin-2 — Second-Generation Leech Antimicrobial Peptide — Kumar et al. (2025)
• Effects of hirudotherapy on liver functions, lipid profile, and insulin sensitivity in rats with metabolic syndrome — Bilden A et al. (2026)
• Hirudotherapy in Medicine and Dentistry — Jha K et al. (2015)
• Medicinal leech therapy (hirudotherapy): a brief overview — Singh A (2010)