In silicoanalysis of a therapeutic target inLeishmania infantum: the guanosine-diphospho-D-mannose pyrophosphorylase

Abstract

Leishmaniases are tropical and sub-tropical diseases for which classical drugs (i.e. antimonials) exhibit toxicity and drug resistance. Such a situation requires to find new chemical series with antileishmanial activity. This work consists in analyzing the structure of a validated target in Leishmania: the GDP-mannose pyrophosphorylase (GDP-MP), an enzyme involved in glycosylation and essential for amastigote survival. By comparing both human and L. infantum GDP-MP 3D homology models, we identified (i) a common motif of amino acids that binds to the mannose moiety of the substrate and, interestingly, (ii) a motif that is specific to the catalytic site of the parasite enzyme. This motif could then be used to design compounds that specifically inhibit the leishmanial GDP-MP, without any effect on the human homolog.

Biochemical analysis of leishmanial and human GDP-Mannose Pyrophosphorylases and selection of inhibitors as new leads

“…The human GDP-MP isoform analyzed in this work is the β2 subunit ( h GDP-MP), which presents a wide tissue distribution, and has a higher identity score for the leishmanial counterparts (∼50%), compared to the β1 subunit (∼46%). While amino acids involved in substrate binding are conserved between Lm GDP-MP and Ld GDP-MP, several differences have been identified in the active site of h GDP-MP 6 , 7 . In order to compare their enzymatic properties, His6-tagged Ld GDP-MP, Lm GDP-MP and h GDP-MP were produced and purified using nickel affinity chromatography (Fig.…”

“…The GDP-mannose Pyrophosphorylase (GDP-MP) is an attractive therapeutic target due to its essential role in amastigote survival in macrophages both in vitro and in vivo and its involvement in the biosynthesis of diverse glycoconjugates necessary for host cell recognition 4 , 5 . Furthermore, by molecular modeling, we identified several structural differences between the parasite and the human orthologs, including the presence of a specific motif in the catalytic pocket, making this enzyme a target of choice for the development of new specific antileishmanial agents 6 , 7 . A high throughput screening performed on L. major GDP-MP allowed the identification of a quinoline derivative, presenting an IC 50 value on the enzyme at the submicromolar range and on intramacrophage parasites at about 20 µM 8 .…”

Study on Experimental Leishmanicidal Activity and in silico of Cytochalasin B

“…The technologies in silico, when compared to the in vitro and in vivo methods, are less expensive, faster, have a higher yield, have a greater reproducibility, and have the potential to reduce the use of animals, 8 in addition to its important applications in the rational planning of potential bioactive compounds, particularly compounds with antileishmanial activity. 9 In this study, the leishmanicidal activity of cytochalasin B (1) ( Figure 1) was studied against a strain of L. amazonensis, as well as the application of the molecular docking technique and computational simulation through classic molecular dynamics (MD). In both assays, cytochalasin B (1) showed good activity.…”

GDP-Mannose Pyrophosphorylase: A Biologically Validated Target for Drug Development Against Leishmaniasis

“…As no GDP-MP crystal could be obtained in Leishmania , molecular models of L. infantum and L. donovani GDP-MP were generated using distinct sequence alignment strategies and were compared with the human counterpart (Pomel et al, 2012; Daligaux et al, 2016a). Both analyses showed a structural conservation of a consensus sequence GXGXRX n K in leishmanial and human GDP-MP corresponding to a pyrophosphorylase signature motif, as well as the F(V)EKP sequence previously described to be part of the GDP-MP active site (Sousa et al, 2008).…”

“…Both analyses showed a structural conservation of a consensus sequence GXGXRX n K in leishmanial and human GDP-MP corresponding to a pyrophosphorylase signature motif, as well as the F(V)EKP sequence previously described to be part of the GDP-MP active site (Sousa et al, 2008). Interestingly, several specific residues have been identified in the catalytic site of both L. infantum and L. donovani GDP-MP compared to the human counterpart (Pomel et al, 2012; Daligaux et al, 2016a). Moreover, GDP-MP sequences share more than 85% of identity in the Leishmania genus.…”