Correlation between the affinity of flavonoids binding to the cytosolic site of Leishmania tropica multidrug transporter and their efficiency to revert parasite resistance to daunomycin

Biochemistry. 1999 Feb 9;38(6):1736-43. doi: 10.1021/bi982455v.


The C-terminal nucleotide-binding domain (NBD2) of a P-glycoprotein-like transporter, encoded by the ltrmdr1 gene in Leishmania tropica and involved in parasite multidrug resistance (MDR), was overexpressed in Escherichia coli as a hexahistidine tagged protein and purified. The L. tropica recombinant domain efficiently bound fluorescent derivatives of ATP, the hydrophobic steroid analogue RU 486, and different classes of flavonoids with the following efficiency: flavone > flavanone > isoflavone > glucorhamnosyl-flavone > chromone. The affinity for flavones was dependent on the presence of hydroxyl groups at positions 5 and 3 and was further increased by a hydrophobic 1,1-dimethylallyl substituent at position 8. When flow cytometry was used to measure daunomycin accumulation in a MDR L. tropica line, a reversing effect was observed with flavones such as dimethylallyl-kaempferide at low concentration or apigenin at higher concentration, but neither with the glucorhamnosyl derivative rutin nor with the isoflavone genistein. The in vivo reversing effect of dimethylallyl-kaempferide was correlated to a high inhibition of MDR cell growth in the presence of daunomycin. The results suggest that flavone inhibition of both daunomycin efflux and parasite growth in the presence of the drug correlates to direct binding of the compound to cytosolic domain of the P-glycoprotein-like transporter.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 1 / genetics
  • ATP Binding Cassette Transporter, Subfamily B, Member 1 / metabolism*
  • ATP-Binding Cassette Transporters / biosynthesis
  • ATP-Binding Cassette Transporters / genetics
  • ATP-Binding Cassette Transporters / isolation & purification
  • Animals
  • Cell Line
  • Cytosol / drug effects
  • Cytosol / metabolism*
  • Daunorubicin / metabolism
  • Daunorubicin / pharmacology*
  • Drug Resistance, Multiple*
  • Flavonoids / metabolism*
  • Flavonoids / pharmacology
  • Leishmania tropica / drug effects
  • Leishmania tropica / growth & development
  • Leishmania tropica / metabolism*
  • Protein Binding / drug effects
  • Protein Structure, Tertiary
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / isolation & purification


  • ATP Binding Cassette Transporter, Subfamily B, Member 1
  • ATP-Binding Cassette Transporters
  • Flavonoids
  • Recombinant Proteins
  • Daunorubicin