scholarly journals Mitochondrial type II NADH dehydrogenase of Plasmodium falciparum is dispensable and not the functional target of putative NDH2 quinolone inhibitors

2018 ◽  
Author(s):  
Hangjun Ke ◽  
Suresh M. Ganesan ◽  
Swati Dass ◽  
Joanne M. Morrisey ◽  
Sovitj Pou ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Antimalarial Drug ◽  
Drug Target ◽  
Nadh Dehydrogenase ◽  
Antimalarial Activity ◽  
Reductase Activity ◽  
Proton Pumping ◽  
Type Ii ◽  
Long Time ◽  
Specific Inhibitors

AbstractThe battle against malaria has been substantially impeded by the recurrence of drug resistance in Plasmodium falciparum, the deadliest human malaria parasite. To counter the problem, novel antimalarial drugs are urgently needed, especially those that target unique pathways of the parasite, since they are less likely to have side effects. The mitochondrial type II NADH dehydrogenase of P. falciparum, PfNDH2 (PF3D7_0915000), has been considered a good prospective antimalarial drug target for over a decade, since malaria parasites lack the conventional multi-subunit NADH dehydrogenase, or Complex I, present in the mammalian mitochondrial electron transport chain (mtETC). Instead, Plasmodium parasites contain a single subunit NDH2, which lacks proton pumping activity and is absent in humans. A significant amount of effort has been expended to develop PfNDH2 specific inhibitors, yet the essentiality of PfNDH2 has not been convincingly verified. Herein, we knocked out PfNDH2 in P. falciparum via a CRISPR/Cas9 mediated approach. Deletion of PfNDH2 does not alter the parasite’s susceptibility to multiple mtETC inhibitors, including atovaquone and ELQ-300. We also show that the antimalarial activity of the fungal NDH2 inhibitor HDQ and its new derivative CK-2-68 is due to inhibition of the parasite cytochrome bc1 complex rather than PfNDH2. These compounds directly inhibit the ubiquinol-cytochrome c reductase activity of the malarial bc1 complex. Our results call into question the validity of PfNDH2 as an antimalarial drug target.ImportanceFor a long time, PfNDH2 has been considered an attractive antimalarial drug target. However, the conclusion that PfNDH2 is essential was based on preliminary and incomplete data. Here we generate a PfNDH2 KO (knockout) parasite in the blood stages of Plasmodium falciparum, showing that the gene is not essential. We also show that previously reported PfNDH2-specific inhibitors kill the parasites primarily via targeting the cytochrome bc1 complex, not PfNDH2. Overall, we provide genetic and biochemical data that help to resolve a long-debated issue in the field regarding the potential of PfNDH2 as an antimalarial drug target.

scholarly journals Physiological relevance, localization and substrate specificity of the alternative (type II) mitochondrial NADH dehydrogenases of Ogataea parapolymorpha

2021 ◽  
Author(s):  
Hannes Juergens ◽  
Álvaro Mielgo-Gómez ◽  
Albert Godoy-Hernández ◽  
Jolanda ter Horst ◽  
Janine M. Nijenhuis ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Respiratory Chain ◽  
Complex I ◽  
Nadh Dehydrogenase ◽  
Physiological Role ◽  
Proton Pumping ◽  
Type Ii ◽  
Respiratory Chains ◽  
Alternative Type ◽  
Nadh Dehydrogenases

AbstractMitochondria from Ogataea parapolymorpha harbor a branched electron-transport chain containing a proton-pumping Complex I NADH dehydrogenase and three alternative (type II) NADH dehydrogenases (NDH2s). To investigate the physiological role, localization and substrate specificity of these enzymes, growth of various NADH dehydrogenase mutants was quantitatively characterized in shake-flask and chemostat cultures, followed by oxygen-uptake experiments with isolated mitochondria. Furthermore, NAD(P)H:quinone oxidoreduction of the three NDH2s were individually assessed. Our findings show that the O. parapolymorpha respiratory chain contains an internal NADH-accepting NDH2 (Ndh2-1/OpNdi1), at least one external NAD(P)H-accepting enzyme and likely additional mechanisms for respiration-linked oxidation of cytosolic NADH. Metabolic regulation appears to prevent competition between OpNdi1 and Complex I for mitochondrial NADH. With the exception of OpNdi1, the respiratory chain of O. parapolymorpha exhibits metabolic redundancy and tolerates deletion of multiple NADH-dehydrogenase genes without compromising fully respiratory metabolism.ImportanceTo achieve high productivity and yields in microbial bioprocesses, efficient use of the energy substrate is essential. Organisms with branched respiratory chains can respire via the energy-efficient proton-pumping Complex I, or make use of alternative NADH dehydrogenases (NDH2s). The yeast Ogataea parapolymorpha contains three uncharacterized, putative NDH2s which were investigated in this work. We show that O. parapolymorpha contains at least one ‘internal’ NDH2, which provides an alternative to Complex I for mitochondrial NADH oxidation, albeit at a lower efficiency. The use of this NDH2 appeared to be limited to carbon excess conditions and the O. parapolymorpha respiratory chain tolerated multiple deletions without compromising respiratory metabolism, highlighting opportunities for metabolic (redox) engineering. By providing a more comprehensive understanding of the physiological role of NDH2s, including insights into their metabolic capacity, orientation and substrate specificity this study also extends our fundamental understanding of respiration in organisms with branched respiratory chains.

scholarly journals Mitochondrial type II NADH dehydrogenase of Plasmodium falciparum (PfNDH2) is dispensable in the asexual blood stages

PLoS ONE ◽  
2019 ◽  
Vol 14 (4) ◽  
pp. e0214023 ◽  
Author(s):  
Hangjun Ke ◽  
Suresh M. Ganesan ◽  
Swati Dass ◽  
Joanne M. Morrisey ◽  
Sovitj Pou ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Nadh Dehydrogenase ◽  
Type Ii

scholarly journals Comparison of Efficacies of Cysteine Protease Inhibitors against Five Strains of Plasmodium falciparum

2001 ◽  
Vol 45 (3) ◽  
pp. 949-951 ◽  
Author(s):  
Ajay Singh ◽  
Philip J. Rosenthal
Keyword(s):  
Plasmodium Falciparum ◽  
Protease Inhibitors ◽  
Cysteine Protease ◽  
Antimalarial Drug ◽  
Drug Target ◽  
Antimalarial Drugs ◽  
Cross Resistance ◽  
Cysteine Protease Inhibitors ◽  
Antimalarial Agents ◽  
Parasite Strains

ABSTRACT Falcipain-2, a cysteine protease and essential hemoglobinase ofPlasmodium falciparum, is a potential antimalarial drug target. We compared the falcipain-2 sequences and sensitivities to cysteine protease inhibitors of five parasite strains that differ markedly in sensitivity to established antimalarial drugs. The sequence of falcipain-2 was highly conserved, and the sensitivities of all of the strains to falcipain-2 inhibitors were very similar. Thus, cross-resistance between cysteine protease inhibitors and other antimalarial agents is not expected in parasites that are now circulating and falcipain-2 remains a promising chemotherapeutic target.

scholarly journals Plasmodium falciparum Niemann-Pick Type C1-Related Protein is a Druggable Target Required for Parasite Membrane Homeostasis

2018 ◽  
Author(s):  
Eva S. Istvan ◽  
Sudipta Das ◽  
Suyash Bhatnagar ◽  
Josh R. Beck ◽  
Edward Owen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Plasmodium Falciparum ◽  
Plasma Membrane ◽  
Small Molecule ◽  
Antimalarial Drug ◽  
Drug Target ◽  
Related Protein ◽  
Immuno Electron Microscopy ◽  
Increased Sensitivity ◽  
Niemann Pick

AbstractPlasmodium parasites possess a protein with homology to Niemann-Pick Type C1 proteins (Plasmodium falciparum Niemann-Pick Type C1-Related protein, PfNCR1). We isolated parasites with resistance-conferring mutations in PfNCR1 during selections with three diverse small-molecule antimalarial compounds and show that the mutations are causative for compound resistance. PfNCR1 protein knockdown results in severely attenuated growth and confers hypersensitivity to the compounds. Compound treatment or protein knockdown leads to increased sensitivity of the parasite plasma membrane (PPM) to the amphipathic glycoside saponin and engenders digestive vacuoles (DVs) that are small and malformed. Immuno-electron microscopy and split-GFP experiments localize PfNCR1 to the PPM. Our experiments show that PfNCR1 activity is critically important for the composition of the PPM and is required for DV biogenesis, suggesting PfNCR1 as a novel antimalarial drug target.

scholarly journals A yeast-based drug discovery platform to identify Plasmodium falciparum type II NADH dehydrogenase inhibitors

2021 ◽  
Author(s):  
Yu Cao ◽  
Chen Sun ◽  
Han Wen ◽  
Mengfei Wang ◽  
Pan Zhu ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Complex I ◽  
Nadh Dehydrogenase ◽  
Specific Inhibitor ◽  
Type I ◽  
Type Ii ◽  
Protein Activity ◽  
Asexual Blood Stage

Conventional methods utilizing in vitro protein activity assay or in vivo parasite survival to screen for malaria inhibitors suffer from high experimental background and/or inconvenience. Here we introduce a yeast-based system to facilitate chemical screen for specific protein or pathway inhibitors. The platform comprises several isogeneic Pichia strains that only differ in the target of interest, so that a compound which inhibits one strain but not the other is implicated in working specifically against the target. We used Plasmodium falciparum NDH2(PfNDH2), a type II NADH dehydrogenase, as a proof of principle to show how well this works. Three isogenic Pichia strains harboring respectively exogeneously introduced PfNDH2, its own complex I (a type I NADH dehydrogenase), and PfNDH2 with its own complex I were constructed. In a pilot screen of more than2000 compounds, we identified a highly specific inhibitor that acts on PfNDH2. This compound poorly inhibit the parasites at the asexual blood stage, however, is highly effective in repressing oocyst maturation in the mosquito stage. Our results demonstrate that the yeast cell based screen platform is feasible, efficient, economical and with very low background noise. Similar strategies could be extended to the functional screen for interacting molecules of other targets.

Characterization of Plasmodium falciparum 6-Phosphogluconate Dehydrogenase as an Antimalarial Drug Target

2018 ◽  
Vol 430 (21) ◽  
pp. 4049-4067 ◽  
Author(s):  
Kristina Haeussler ◽  
Karin Fritz-Wolf ◽  
Max Reichmann ◽  
Stefan Rahlfs ◽  
Katja Becker
Keyword(s):  
Plasmodium Falciparum ◽  
Antimalarial Drug ◽  
Drug Target ◽  
Phosphogluconate Dehydrogenase

scholarly journals Type II NADH dehydrogenase of the respiratory chain of Plasmodium falciparum and its inhibitors

2009 ◽  
Vol 19 (3) ◽  
pp. 972-975 ◽  
Author(s):  
Carolyn K. Dong ◽  
Vishal Patel ◽  
Jimmy C. Yang ◽  
Jeffrey D. Dvorin ◽  
Manoj T. Duraisingh ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Respiratory Chain ◽  
Nadh Dehydrogenase ◽  
Type Ii
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