scholarly journals Identification of Plasmodium falciparum Mitochondrial Malate: Quinone Oxidoreductase Inhibitors from the Pathogen Box

Genes ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 471 ◽  
Author(s):  
Xinying Wang ◽  
Yukiko Miyazaki ◽  
Daniel Ken Inaoka ◽  
Endah Dwi Hartuti ◽  
Yoh-Ichi Watanabe ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Antimalarial Drug ◽  
Drug Target ◽  
Drug Targets ◽  
Tricarboxylic Acid Cycle ◽  
Drug Resistant ◽  
Quinone Oxidoreductase ◽  
Mitochondrial Inner Membrane ◽  
Transport Chain ◽  
Urgent Task

Malaria is one of the three major global health threats. Drug development for malaria, especially for its most dangerous form caused by Plasmodium falciparum, remains an urgent task due to the emerging drug-resistant parasites. Exploration of novel antimalarial drug targets identified a trifunctional enzyme, malate quinone oxidoreductase (MQO), located in the mitochondrial inner membrane of P. falciparum (PfMQO). PfMQO is involved in the pathways of mitochondrial electron transport chain, tricarboxylic acid cycle, and fumarate cycle. Recent studies have shown that MQO is essential for P. falciparum survival in asexual stage and for the development of experiment cerebral malaria in the murine parasite P. berghei, providing genetic validation of MQO as a drug target. However, chemical validation of MQO, as a target, remains unexplored. In this study, we used active recombinant protein rPfMQO overexpressed in bacterial membrane fractions to screen a total of 400 compounds from the Pathogen Box, released by Medicines for Malaria Venture. The screening identified seven hit compounds targeting rPfMQO with an IC50 of under 5 μM. We tested the activity of hit compounds against the growth of 3D7 wildtype strain of P. falciparum, among which four compounds showed an IC50 from low to sub-micromolar concentrations, suggesting that PfMQO is indeed a potential antimalarial drug target.

scholarly journals Biochemical Studies of Mitochondrial Malate: Quinone Oxidoreductase from Toxoplasma gondii

2021 ◽  
Vol 22 (15) ◽  
pp. 7830
Author(s):  
Rajib Acharjee ◽  
Keith K. Talaam ◽  
Endah D. Hartuti ◽  
Yuichi Matsuo ◽  
Takaya Sakura ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Drug Target ◽  
Tricarboxylic Acid Cycle ◽  
Expression System ◽  
Protozoan Parasite ◽  
New Drugs ◽  
Quinone Oxidoreductase ◽  
Steady State Kinetics ◽  
Transport Chain ◽  
Effective Drugs

Toxoplasma gondii is a protozoan parasite that causes toxoplasmosis and infects almost one-third of the global human population. A lack of effective drugs and vaccines and the emergence of drug resistant parasites highlight the need for the development of new drugs. The mitochondrial electron transport chain (ETC) is an essential pathway for energy metabolism and the survival of T. gondii. In apicomplexan parasites, malate:quinone oxidoreductase (MQO) is a monotopic membrane protein belonging to the ETC and a key member of the tricarboxylic acid cycle, and has recently been suggested to play a role in the fumarate cycle, which is required for the cytosolic purine salvage pathway. In T. gondii, a putative MQO (TgMQO) is expressed in tachyzoite and bradyzoite stages and is considered to be a potential drug target since its orthologue is not conserved in mammalian hosts. As a first step towards the evaluation of TgMQO as a drug target candidate, in this study, we developed a new expression system for TgMQO in FN102(DE3)TAO, a strain deficient in respiratory cytochromes and dependent on an alternative oxidase. This system allowed, for the first time, the expression and purification of a mitochondrial MQO family enzyme, which was used for steady-state kinetics and substrate specificity analyses. Ferulenol, the only known MQO inhibitor, also inhibited TgMQO at IC50 of 0.822 μM, and displayed different inhibition kinetics compared to Plasmodium falciparum MQO. Furthermore, our analysis indicated the presence of a third binding site for ferulenol that is distinct from the ubiquinone and malate sites.

scholarly journals A specific non-bisphosphonate inhibitor of the bifunctional farnesyl/geranylgeranyl diphosphate synthase in malaria parasites

2017 ◽  
Author(s):  
Jolyn E. Gisselberg ◽  
Zachary Herrera ◽  
Lindsey Orchard ◽  
Manuel Llinás ◽  
Ellen Yeh
Keyword(s):  
Plasmodium Falciparum ◽  
Physicochemical Properties ◽  
Small Molecule ◽  
Antimalarial Drug ◽  
Drug Target ◽  
Drug Targets ◽  
Geranylgeranyl Diphosphate Synthase ◽  
Geranylgeranyl Diphosphate ◽  
Malaria Parasites ◽  
Starting Point

SummaryIsoprenoid biosynthesis is essential for Plasmodium falciparum (malaria) parasites and contains multiple validated antimalarial drug targets, including a bifunctional farnesyl and geranylgeranyl diphosphate synthase (FPPS/GGPPS). We identified MMV019313 as an inhibitor of PfFPPS/GGPPS. Though PfFPPS/GGPPS is also inhibited by a class of bisphosphonate drugs, MMV019313 has significant advantages for antimalarial drug development. MMV019313 has superior physicochemical properties compared to charged bisphosphonates that have poor bioavailability and strong bone affinity. We also show that it is highly selective for PfFPPS/GGPPS and showed no activity against human FPPS or GGPPS. Inhibition of PfFPPS/GGPPS by MMV019313, but not bisphosphonates, was disrupted in an S228T variant, demonstrating that MMV019313 and bisphosphonates have distinct modes-of-inhibition against PfFPPS/GGPPS. Altogether MMV019313 is the first specific, non-bisphosphonate inhibitor of PfFPPS/GGPPS. Our findings uncover a new small molecule binding site in this important antimalarial drug target and provide a promising starting point for development of Plasmodium-specific FPPS/GGPPS inhibitors.

scholarly journals In Silico Knockout Screening of Plasmodium falciparum Reactions and Prediction of Novel Essential Reactions by Analysing the Metabolic Network

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jelili Oyelade ◽  
Itunuoluwa Isewon ◽  
Efosa Uwoghiren ◽  
Olufemi Aromolaran ◽  
Olufunke Oladipupo
Keyword(s):  
Infectious Disease ◽  
Plasmodium Falciparum ◽  
Metabolic Network ◽  
Antimalarial Drug ◽  
Drug Target ◽  
Drug Targets ◽  
New Drugs ◽  
Biological Evidence ◽  
Essential Reactions ◽  
Extensive List

Malaria is an infectious disease that affects close to half a million individuals every year and Plasmodium falciparum is a major cause of malaria. The treatment of this disease could be done effectively if the essential enzymes of this parasite are specifically targeted. Nevertheless, the development of the parasite in resisting existing drugs now makes discovering new drugs a core responsibility. In this study, a novel computational model that makes the prediction of new and validated antimalarial drug target cheaper, easier, and faster has been developed. We have identified new essential reactions as potential targets for drugs in the metabolic network of the parasite. Among the top seven (7) predicted essential reactions, four (4) have been previously identified in earlier studies with biological evidence and one (1) has been with computational evidence. The results from our study were compared with an extensive list of seventy-seven (77) essential reactions with biological evidence from a previous study. We present a list of thirty-one (31) potential candidates for drug targets in Plasmodium falciparum which includes twenty-four (24) new potential candidates for drug targets.

Antimalarial Drug Targets and Drugs Targeting Dolichol Metabolic Pathway of Plasmodium falciparum

2014 ◽  
Vol 15 (4) ◽  
pp. 374-409 ◽  
Author(s):  
Tabish Qidwai ◽  
Avantika Priya ◽  
Nihal Khan ◽  
Himanshu Tripathi ◽  
Feroz Khan ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Metabolic Pathway ◽  
Antimalarial Drug ◽  
Drug Targets

scholarly journals A Chemical Rescue Screen Identifies a Plasmodium falciparum Apicoplast Inhibitor Targeting MEP Isoprenoid Precursor Biosynthesis

2014 ◽  
Vol 59 (1) ◽  
pp. 356-364 ◽  
Author(s):  
Wesley Wu ◽  
Zachary Herrera ◽  
Danny Ebert ◽  
Katie Baska ◽  
Seok H. Cho ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Antimalarial Drug ◽  
Drug Targets ◽  
Specific Activity ◽  
Drug Candidate ◽  
Content Type ◽  
Chemical Rescue ◽  
Growth Inhibitory ◽  
Parasite Populations

ABSTRACTThe apicoplast is an essential plastid organelle found inPlasmodiumparasites which contains several clinically validated antimalarial-drug targets. A chemical rescue screen identified MMV-08138 from the “Malaria Box” library of growth-inhibitory antimalarial compounds as having specific activity against the apicoplast. MMV-08138 inhibition of blood-stagePlasmodium falciparumgrowth is stereospecific and potent, with the most active diastereomer demonstrating a 50% effective concentration (EC50) of 110 nM. Whole-genome sequencing of 3 drug-resistant parasite populations from two independent selections revealed E688Q and L244I mutations inP. falciparumIspD, an enzyme in the MEP (methyl-d-erythritol-4-phosphate) isoprenoid precursor biosynthesis pathway in the apicoplast. The active diastereomer of MMV-08138 directly inhibited PfIspD activityin vitrowith a 50% inhibitory concentration (IC50) of 7.0 nM. MMV-08138 is the first PfIspD inhibitor to be identified and, together with heterologously expressed PfIspD, provides the foundation for further development of this promising antimalarial drug candidate lead. Furthermore, this report validates the use of the apicoplast chemical rescue screen coupled with target elucidation as a discovery tool to identify specific apicoplast-targeting compounds with new mechanisms of action.

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 Genetic ablation of the mitochondrial ribosome in Plasmodium falciparum sensitizes the human malaria parasite to antimalarial drugs targeting mitochondrial functions

2020 ◽  
Author(s):  
Liqin Ling ◽  
Maruthi Mulaka ◽  
Justin Munro ◽  
Swati Dass ◽  
Michael W. Mather ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Ribosomal Proteins ◽  
Drug Targets ◽  
Small Subunit ◽  
Rrna Genes ◽  
Pyrimidine Nucleotides ◽  
Genetic Ablation ◽  
Mitochondrial Inner Membrane ◽  
Mitochondrial Functions ◽  
Mitochondrial Ribosome

ABSTRACTThe mitochondrion of malaria parasites contains clinically validated drug targets. Within Plasmodium spp., the mitochondrial DNA (mtDNA) is only 6 kb long, being the smallest mitochondrial genome among all eukaryotes. The mtDNA encodes only three proteins of the mitochondrial electron transport chain and ∼ 27 small, fragmented rRNA genes in length of 22-195 nucleotides. The rRNA fragments are thought to form a mitochondrial ribosome (mitoribosome), together with ribosomal proteins imported from the cytosol. The mitoribosome of Plasmodium falciparum has been shown to be essential for maintenance of the mitochondrial membrane potential and parasite viability. However, the role of mitoribosomes in sustaining the metabolic status of the parasite mitochondrion remains unknown. Here, among the 14 annotated mitoribosomal proteins of the small subunit of P. falciparum, we verified the localization and tested the essentiality of three candidates (PfmtRPS12, PfmtRPS17, PfmtRPS18), employing a CRISPR/Cas9 mediated conditional knockdown tool. Using immuno-electron microscopy, we provided evidence that the mitoribosome is closely associated with the mitochondrial inner membrane in the parasite. Upon knockdown of the mitoribosome, the parasites became hypersensitive to inhibitors targeting the bc1 complex, dihydroorotate dehydrogenase and F1Fo ATP synthase complex. Furthermore, knockdown of the mitoribosome blocked the pyrimidine biosynthesis pathway and reduced the pool of pyrimidine nucleotides. Together, our data suggest that disruption of the P. falciparum mitoribosome compromises the metabolic capability of the mitochondrion, rendering the parasite hypersensitive to a panel of inhibitors targeting mitochondrial functions.

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