De novo design approaches targeting an envelope protein pocket to identify small molecules against dengue virus

Eur J Med Chem. 2019 Nov 15:182:111628. doi: 10.1016/j.ejmech.2019.111628. Epub 2019 Aug 15.

Abstract

Dengue fever is a mosquito-borne viral disease that has become a major public health concern worldwide. This disease presents with a wide range of clinical manifestations, from a mild cold-like illness to the more serious hemorrhagic dengue fever and dengue shock syndrome. Currently, neither an approved drug nor an effective vaccine for the treatment are available to fight the disease. The envelope protein (E) is a major component of the virion surface. This protein plays a key role during the viral entry process, constituting an attractive target for the development of antiviral drugs. The crystal structure of the E protein reveals the existence of a hydrophobic pocket occupied by the detergent n-octyl-β-d-glucoside (β-OG). This pocket lies at the hinge region between domains I and II and is important for the low pH-triggered conformational rearrangement required for the fusion of the virion with the host's cell. Aiming at the design of novel molecules which bind to E and act as virus entry inhibitors, we undertook a de novo design approach by "growing" molecules inside the hydrophobic site (β-OG). From more than 240000 small-molecules generated, the 2,4 pyrimidine scaffold was selected as the best candidate, from which one synthesized compound displayed micromolar activity. Molecular dynamics-based optimization was performed on this hit, and thirty derivatives were designed in silico, synthesized and evaluated on their capacity to inhibit dengue virus entry into the host cell. Four compounds were found to be potent antiviral compounds in the low-micromolar range. The assessment of drug-like physicochemical and in vitro pharmacokinetic properties revealed that compounds 3e and 3h presented acceptable solubility values and were stable in mouse plasma, simulated gastric fluid, simulated intestinal fluid, and phosphate buffered saline solution.

Keywords: Anti-Dengue virus compounds; De novo design; Molecular dynamics; Pharmacokinetics in vitro properties.

MeSH terms

  • A549 Cells
  • Animals
  • Antiviral Agents / chemical synthesis
  • Antiviral Agents / chemistry
  • Antiviral Agents / pharmacology*
  • Cell Line
  • Cell Survival / drug effects
  • Dengue Virus / drug effects*
  • Dengue Virus / metabolism
  • Dose-Response Relationship, Drug
  • Drug Design*
  • Humans
  • Mice
  • Microbial Sensitivity Tests
  • Models, Molecular
  • Molecular Structure
  • Small Molecule Libraries / chemical synthesis
  • Small Molecule Libraries / chemistry
  • Small Molecule Libraries / pharmacology*
  • Solubility
  • Structure-Activity Relationship
  • Viral Envelope Proteins / antagonists & inhibitors*
  • Viral Envelope Proteins / metabolism

Substances

  • Antiviral Agents
  • Small Molecule Libraries
  • Viral Envelope Proteins