화학공학소재연구정보센터
Langmuir, Vol.33, No.30, 7529-7537, 2017
The Effects of Quinoline and Non-Quinoline Inhibitors on the Kinetics of Lipid-Mediated beta-Hematin Crystallization
The throughput of a biomimetic lipid-mediated assay used to investigate the effects of inhibitors on the kinetics of beta-hematin formation has been optimized through the use of 24-well microplates. The rate constant for beta-hematin formation mediated by monopalmitoyl-rac-glycerol was reduced from 0.17 +/- 0.04 min(-1) previously measured in Falcon tubes to 0.019 0.002 min(-1) in the optimized assay. While this necessitated longer incubation times, transferring aliquots from multiple 24-well plates to a single 96-well plate for final absorbance measurements actually improved the overall turnaround time per inhibitor. This assay has been applied to investigate the effects of four clinically relevant antimalarial drugs (chloroquine, amodiaquine, quinidine, and quinine) as well as several short-chain 4-aminoquinoline derivatives and non-quinoline (benzamide) compounds on the kinetics of beta-hematin formation. The adsorption strength of these inhibitors to crystalline beta-hematin (K-ads) was quantified using a theoretical kinetic model that is based on the Avrami equation and the Langmuir isotherm. Statistically significant linear correlations between lipid-mediated beta-hematin inhibitory activity and K-ads values for quinoline (r(2) = 0.76, P-value = 0.0046) and non-quinoline compounds (r(2) = 0.99, P-stat = 0.0006), as well as between parasite inhibitory activity (D10) and K-ads values for quinoline antimalarial drugs and short-chain chloroquine derivatives (r(2) = 0.64, P-value = 0.0098), provide a strong indication that drug action involves adsorption to the surface of beta-hematin crystals. Independent support in this regard is provided by experiments that spectrophetorrietrically monitor the direct adsorption of antimalarial drugs to preformed beta-hematin.