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. 2021 Jul;105(13):5471-5489.
doi: 10.1007/s00253-021-11434-4. Epub 2021 Jul 12.

Biochemical and structural insights into 6-phosphogluconate dehydrogenase from Leishmania donovani

Pranay Jakkula  1 , Bandigi Narsimulu  1 , Insaf Ahmed Qureshi  2
Affiliations

Biochemical and structural insights into 6-phosphogluconate dehydrogenase from Leishmania donovani

Pranay Jakkula et al. Appl Microbiol Biotechnol. 2021 Jul.

Abstract

6-phosphogluconate dehydrogenase (6PGDH) participates in pentose phosphate pathway of glucose metabolism by catalyzing oxidative decarboxylation of 6-phsophogluconate (6PG) and its absence has been lethal for several eukaryotes. Despite being a validated drug target in many organisms like Plasmodium, the enzyme has not been explored in leishmanial parasites. In the present study, 6PGDH of Leishmania donovani (Ld6PGDH) is cloned and purified followed by its characterization using biochemical and structural approaches. Ld6PGDH lacks the glycine-serine-rich sequence at its C-terminal that is present in other eukaryotes including humans. Leishmanial 6PGDH possesses more affinity for substrate (6PG) and cofactor (NADP) in comparison to that of human. The enzymatic activity is inhibited by gentamicin and cefuroxime through competitive mode with functioning more potently towards leishmanial 6PGDH than its human counterpart. CD analysis has shown higher α-helical content in the secondary structure of Ld6PGDH, while fluorescence studies revealed that tryptophan residues are not completely accessible to solvent environment. The three-dimensional structure was generated through homology modelling and docked with substrate and cofactor. The docking studies demonstrated two separate binding pockets for 6PG and NADP with higher affinity for the cofactor binding, and Asn105 is interacting with substrate as well as the cofactor. Additionally, MD simulation has shown complexes of Ld6PGDH with 6PG and NADP to be more stable than its apo form. Altogether, the present study might provide the foundation to investigate this enzyme as potential target against leishmaniasis. KEY POINTS: • Ld6PGDH enzymatic activity is competitively inhibited by gentamicin and cefuroxime. • It displays more helical contents and all structural characteristics of 6PGDH family. • Interaction studies demonstrate higher affinity of cofactor than substrate for Ld6PGDH.

Keywords: 6-phosphogluconate dehydrogenase; Antibiotics; Enzyme kinetics; Leishmania donovani; Pentose phosphate pathway; Structural insights.

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References

    1. Adams MJ, Ellis GH, Gover S, Naylor CE, Phillips C (1994) Crystallographic study of coenzyme, coenzyme analogue and substrate binding in 6-phosphogluconate dehydrogenase: implications for NADP specificity and the enzyme mechanism. Structure 2:651–668. https://doi.org/10.1016/s0969-2126(00)00066-6 - DOI - PubMed
    1. Adem S, Ciftci M (2016) Purification and biochemical characterization of glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and glutathione reductase from rat lung and inhibition effects of some antibiotics. J Enzyme Inhib Med Chem 31:1342–1348. https://doi.org/10.3109/14756366.2015.1132711 - DOI - PubMed
    1. Akyüz M, Erat M, Ciftçi M, Gümüştekin K, Bakan N (2004) Effects of some antibiotics on human erythrocyte 6-phosphogluconate dehydrogenase: an in vitro and in vivo study. J Enzyme Inhib Med Chem 19:361–365. https://doi.org/10.1080/14756360409162451 - DOI - PubMed
    1. Allmann S, Morand P, Ebikeme C, Gales L, Biran M, Hubert J, Brennand A, Mazet M, Franconi JM, Michels PA, Portais JC, Boshart M, Bringaud F (2013) Cytosolic NADPH homeostasis in glucose-starved procyclic Trypanosoma brucei relies on malic enzyme and the pentose phosphate pathway fed by gluconeogenic flux. J Biol Chem 288:18494–18505. https://doi.org/10.1074/jbc.M113.462978 - DOI - PubMed - PMC
    1. Andreini C, Bertini I, Cavallaro G, Holliday GL, Thornton JM (2008) Metal ions in biological catalysis: from enzyme databases to general principles. J Biol Inorg Chem 13:1205–1218. https://doi.org/10.1007/s00775-008-0404-5 - DOI - PubMed

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