Molecular modeling and docking analysis of Entamoeba histolytica glyceraldehyde-3 phosphate dehydrogenase, a potential target enzyme for anti-protozoal drug development

The enzymes of the glycolytic pathway constitute an excellent target for the design of new anti-protozoal agents; glyceraldehyde-3 phosphate dehydrogenase catalyzes the reversible oxidative phosphorylation of d-glyceraldehyde 3-phosphate (GAP) into d-glycerate 1,3-bisphosphate (1,3-diPG) in the presence of NAD+ and inorganic phosphate (P(i)). The prediction of three-dimensional structure of Entamoeba histolytica and the docking of the coumarins were performed using the crystal structure of glyceraldehyde-3 phosphate dehydrogenase from Leishmania mexicana as template. Energy minimization of the whole complex showed, as expected, that most of the template interactions are preserved in the Entamoeba structure, except for SER178, ARG220 and THR167. However, novel interactions involving ILE 193 and THR 173 were also observed.