New peptidomimetic rhodesain inhibitors with improved selectivity towards human cathepsins

Eur J Med Chem. 2022 Aug 5:238:114460. doi: 10.1016/j.ejmech.2022.114460. Epub 2022 May 14.

Abstract

Parasitic cysteine proteases such as rhodesain (TbCatL) from Trypanosoma brucei rhodesiense are relevant targets for developing new potential drugs against parasitic diseases (e. g. Human African Trypanosomiasis). Designing selective inhibitors for parasitic cathepsins can be challenging as they share high structural similarities with human cathepsins. In this paper, we describe the development of novel peptidomimetic rhodesain inhibitors by applying a structure-based de novo design approach and molecular docking protocols. The inhibitors with a new scaffold in P2 and P3 position display high selectivity towards trypanosomal rhodesain over human cathepsins L and B and high antitrypanosomal activity. Vinylsulfonate 2a has emerged as a potent rhodesain inhibitor (k2nd = 883 • 103 M-1 s-1) with single-digit nanomolar binding affinity (Ki = 9 nM) and more than 150-fold selectivity towards human cathepsins and it thus constitutes an interesting starting compound for the further development of selective drugs against Human African Trypanosomiasis.

Keywords: Cathepsins; Inhibitors; Molecular docking; Rhodesain; Trypanosomes; de-novo design.

MeSH terms

  • Animals
  • Cathepsins
  • Cysteine Endopeptidases
  • Cysteine Proteinase Inhibitors / chemistry
  • Humans
  • Molecular Docking Simulation
  • Peptidomimetics* / pharmacology
  • Peptidomimetics* / therapeutic use
  • Structure-Activity Relationship
  • Trypanocidal Agents* / pharmacology
  • Trypanosoma brucei brucei* / metabolism
  • Trypanosomiasis, African* / drug therapy

Substances

  • Cysteine Proteinase Inhibitors
  • Peptidomimetics
  • Trypanocidal Agents
  • Cathepsins
  • Cysteine Endopeptidases
  • rhodesain