Faculty Collaboration Database

Designing allosteric regulators of thrombin. Monosulfated benzofuran dimers selectively interact with Arg173 of exosite 2 to induce inhibition. J Med Chem 2012 Aug 09;55(15):6888-97

Date

07/14/2012

Pubmed ID

22788964

Pubmed Central ID

PMC3416887

DOI

10.1021/jm300670q

Scopus ID

2-s2.0-84864953109 (requires institutional sign-in at Scopus site)   35 Citations

Abstract

Earlier, we reported on the design of sulfated benzofuran dimers (SBDs) as allosteric inhibitors of thrombin (Sidhu et al. J. Med. Chem.201154 5522-5531). To identify the site of binding of SBDs, we studied thrombin inhibition in the presence of exosite 1 and 2 ligands. Whereas hirudin peptide and heparin octasaccharide did not affect the IC(50) of thrombin inhibition by a high affinity SBD, the presence of full-length heparin reduced inhibition potency by 4-fold. The presence of γ' fibrinogen peptide, which recognizes Arg93, Arg97, Arg173, Arg175, and other residues, resulted in a loss of affinity that correlated with the ideal Dixon-Webb competitive profile. Replacement of several arginines and lysines of exosite 2 with alanine did not affect thrombin inhibition potency, except for Arg173, which displayed a 22-fold reduction in IC(50). Docking studies suggested a hydrophobic patch around Arg173 as a plausible site of SBD binding to thrombin. The absence of the Arg173-like residue in factor Xa supported the observed selectivity of inhibition by SBDs. Cellular toxicity studies indicated that SBDs are essentially nontoxic to cells at concentrations as high as 250 mg/kg. Overall, the work presents the localization of the SBD binding site, which could lead to allosteric modulators of thrombin that are completely different from all clinically used anticoagulants.

Author List

Abdel Aziz MH, Sidhu PS, Liang A, Kim JY, Mosier PD, Zhou Q, Farrell DH, Desai UR

Author

Philip Mosier PhD Assistant Professor in the School of Pharmacy Administration department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Allosteric Regulation
Anticoagulants
Arginine
Arylsulfonates
Benzofurans
Binding Sites
Cell Line
Dimerization
Factor Xa Inhibitors
Fibrinogen
Heparin
Humans
Kinetics
Models, Molecular
Mutation
Protein Binding
Recombinant Proteins
Structure-Activity Relationship
Thrombin