Comparative Structural Analysis and Kinetic Properties of Lactate Dehydrogenases from the Four Species of Human Malarial Parasites

Abstract

Parasite lactate dehydrogenase (pLDH) is a potential drug target for new antimalarials owing to parasite dependence on glycolysis for ATP production. The pLDH from all four species of human malarial parasites were cloned, expressed, and analyzed for structural and kinetic properties that might be exploited for drug development. pLDH from Plasmodium vivax, malariae, and ovale exhibit 90-92% identity to pLDH from Plasmodium falciparum. Catalytic residues are identical. Resides I250 and T246, conserved in most LDH, are replaced by proline in all pLDH. The pLDH contain the same five-amino acid insert (DKEWN) in the substrate specificity loops. Within the cofactor site, pLDH from P. falciparum and P. malariae are identical, while pLDH from P. vivax and P. ovale have one substitution. Homology modeling of pLDH from P. vivax, ovale, and malariae with the crystal structure of pLDH from P. falciparum gave nearly identical structures. Nevertheless, the kinetic properties and sensitivities to inhibitors targeted to the cofactor binding site differ significantly. Michaelis constants for pyruvate and lactate differ 8-9-fold; Michaelis constants for NADH, NAD(+), and the NAD(+) analogue 3-acetylpyridine adenine dinucleotide differ up to 4-fold. Dissociation constants for the inhibitors differ up to 21-fold. Molecular docking studies of the binding of the inhibitors to the cofactor sites of all four pLDH predict similar orientations, with the docked ligands positioned at the nicotinamide end of the cofactor site. pH studies indicate that inhibitor binding is independent of pH in the pH 6-8 range, suggesting that differences in dissociation constants for a specific inhibitor are not due to altered active site pK values among the four pLDH.

Single Mutation in Shine-Dalgarno-Like Sequence Present in the Amino Terminal of Lactate Dehydrogenase of Plasmodium Effects the Production of an Eukaryotic Protein Expressed in a Prokaryotic System

“…Nucleotide Sequence Alignment of the Sequence Upstream of the Third Methionine from LDH of Plasmodium LDH gene was cloned from some different Plasmodium species [7,29,30,33,34]. A nucleotide sequence alignment was made between the upstream sequence of the 3rd methionine of different species of Plasmodium species and given in Table 1.…”

Update on Rapid Diagnostic Testing for Malaria

“…P. falciparum-specific monoclonal antibodies have been developed for histidine-rich protein 2 (HRP-2) and P. falciparum lactate dehydrogenase, while P. vivax-specific monoclonal antibodies have undergone limited evaluation (3,6,27). Targets conserved across all human malarias (pan-Plasmodium antigens) have been identified on Plasmodium lactate dehydrogenase (PLDH) and aldolase enzymes (11,27,52,53).…”

The Potential of Secondary Metabolites from Plants as Drugs or Leads against Protozoan Neglected Diseases—Part III: In-Silico Molecular Docking Investigations

“…These workers found ochrolifuanine A, chrobisiamone A, ailanthinone, korupensamine A, butyraxanthone B, ancistrolikokine A, calothwaitesixanthone, 7-deacetylkhivorin, 5-prenylbutein, methyl 6-hydroxyangolensate, and aulacocarpin A (Figure 14), to show notable docking energies (i.e., lower than the co-crystallized inhibitor WR99210). Plasmodium lactate dehydrogenase has been identified as a potential drug target for antimalarials due to parasite dependence on glycolysis for ATP production [412]. Molecular docking of the tea flavonoid gallocatechin ( Figure 15) to P. falciparum lactate dehydrogenase revealed strong docking, more strongly than either chloroquine or mefloquine, to the NADH binding site of the enzyme [413].…”

“…Using molecular docking (AutoDock) coupled with three-dimensional quantitative structure activity relationships (3D-QSAR), Wadhwa and co-workers identified five phytochemicals (3α,20-lupanediol, ergosterol peroxide, 24-methylenecycloartan-3-ol, 2′-epicycloisobrachycoumarinone epoxide, and atalaphyllidine, Figure 16) as potential PfENR inhibitors [417]. Plasmodium lactate dehydrogenase has been identified as a potential drug target for antimalarials due to parasite dependence on glycolysis for ATP production [412]. Molecular docking of the tea flavonoid gallocatechin ( Figure 15) to P. falciparum lactate dehydrogenase revealed strong docking, more strongly than either chloroquine or mefloquine, to the NADH binding site of the enzyme [413].…”

“…Glycyrrhetic acid (Figure 4) has exhibited notable (IC 50 1.69 µg/mL) in vitro antiplasmodial activity against P. falciparum, and docking studies (Discovery Studio) have also shown glycyrretic acid to dock moderately well to P. falciparum lactate dehydrogenase [414]. Plasmodium lactate dehydrogenase has been identified as a potential drug target for antimalarials due to parasite dependence on glycolysis for ATP production [412]. Molecular docking of the tea flavonoid gallocatechin ( Figure 15) to P. falciparum lactate dehydrogenase revealed strong docking, more strongly than either chloroquine or mefloquine, to the NADH binding site of the enzyme [413].…”