How a β-D-glucoside side chain enhances binding affinity to thrombin of inhibitors bearing 2-chlorothiophene as P1 moiety: crystallography, fragment deconstruction study, and evaluation of antithrombotic properties

J Med Chem. 2014 Oct 23;57(20):8563-75. doi: 10.1021/jm5010754. Epub 2014 Oct 14.

Abstract

The β-d-glucose-containing compound 3, bearing 2-chlorothiophene and 1-isopropylpiperidine moieties as binders of the S1 and S4 pockets, respectively, proved to be potent competitive inhibitor of factor Xa (fXa, Ki = 0.090 nM) and thrombin (fIIa, Ki = 100 nM). The potency of 3 increases, over the parent compound 1, against fIIa (110-fold), much more than against fXa (7-fold). Experimental deconstruction of 3 into smaller fragments revealed a binding cooperativity of the P3/P4 and propylene-linked β-d-glucose fragments, stronger in fIIa (15.5 kJ·mol(-1)) than in fXa (2.8 kJ·mol(-1)). The crystal structure of human fIIa in complex with 3 revealed a binding mode including a strong H-bond network between the glucose O1', O3', and O5' and two critical residues, namely R221a and K224, belonging to the Na(+)-binding site which may allosterically perturb the specificity sites. The potential of 3 as antithrombotic agent was supported by its ability to inhibit thrombin generation and to stimulate fibrinolysis at submicromolar concentration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anticoagulants / chemistry
  • Anticoagulants / pharmacology
  • Antithrombins / chemistry*
  • Antithrombins / metabolism
  • Antithrombins / pharmacology*
  • Binding Sites
  • Chemistry Techniques, Synthetic
  • Crystallography, X-Ray
  • Dose-Response Relationship, Drug
  • Factor Xa Inhibitors / chemistry
  • Factor Xa Inhibitors / pharmacology
  • Fibrin / metabolism
  • Fibrinolysis / drug effects
  • Glucosides / chemistry*
  • Humans
  • Hydrogen Bonding
  • Models, Molecular
  • Structure-Activity Relationship
  • Thiophenes / chemistry*
  • Thrombin / chemistry
  • Thrombin / metabolism

Substances

  • Anticoagulants
  • Antithrombins
  • Factor Xa Inhibitors
  • Glucosides
  • Thiophenes
  • Fibrin
  • Thrombin