title: Screening and In Vitro Evaluation of Potential Plasmodium falciparum Leucyl Aminopeptidase Inhibitors.
abstract: BACKGROUND
  Plasmodium falciparum leucyl aminopeptidase (PfA-M17) regulates the intracellular pool of amino acids required for the growth and development of parasites. Thus, PfA-M17 is a promising target for anti-malarial drug development.
  
  
  METHODS
  In the present study, structure-based drug design was used to identify novel PfA-M17 inhibitors, which were subsequently validated by in vitro PfA-M17 and human LAP3 enzyme inhibition assay. A library of 3,147,882 compounds was screened using receptor-based virtual screening against the active site of PfA-M17, and three levels of accuracy were used: high-throughput virtual screening, gridbased ligand docking with energetics (Glide standard precision) and Glide extra precision.
  
  
  RESULTS
  Seventeen screened compounds were selected and tested in the rPfA-M17 enzyme inhibition assay. Of these nine compounds were found to be effective inhibitors. To test the target activity, all nine PfA-M17 inhibitors were tested against rhLAP3, the human homolog of PfA-M17. One compound (compound 2) was found to be moderately effective against PfA-M17 (Ki = 287 μM) with limited inhibitory activity against hLAP3 (Ki of 4,464 μM). Subsequently, induced fit docking and pharmacophore modelling were used to further understand more precise ligand-protein interactions in the protein-inhibitor complexes.
  
  
  CONCLUSIONS
  Among the 9 effective PfA-M17 inhibitors, 5 compounds were found effective in the P. falciparum schizont maturation inhibition (SMI) assay. A good correlation (r =0.83) was observed between the rPfA-M17 enzyme inhibition concentration and SMI assay.
authors.forename: Meenakshi
authors.initials: M
authors.lastname: Chaudhary
authors.forename: Vineeta
authors.initials: V
authors.lastname: Singh
authors.forename: Anup R
authors.initials: AR
authors.lastname: Anvikar
authors.affiliation: School of Biotechnology, Gautam Buddha University, Greater Noida, 201312, India. shaktis@gbu.ac.in.
authors.forename: Shakti
authors.initials: S
authors.lastname: Sahi
mesh_terms: D000962:Antimalarials / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D001665:Binding Sites; D015195:Drug Design; D057166:High-Throughput Screening Assays; D007700:Kinetics; D007931:Leucyl Aminopeptidase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D008024:Ligands; D016778:Malaria, Falciparum / Q000188:drug therapy* / Q000469:parasitology; D062105:Molecular Docking Simulation; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000201:enzymology; D011480:Protease Inhibitors / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D011485:Protein Binding; D011487:Protein Conformation; D015800:Protozoan Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D054852:Small Molecule Libraries; D013329:Structure-Activity Relationship
chemical_list: D000962:Antimalarials; D008024:Ligands; D011480:Protease Inhibitors; D015800:Protozoan Proteins; D054852:Small Molecule Libraries; D007931:Leucyl Aminopeptidase