Exploring Different Drug Targets Responsible for the Inhibitory Activity of N, N'-Substituted Diamine Derivative in Leishmania

The genome sequence of Leishmania has given rise to diverse novel drug targets and their identification remains the first step in drug discovery. The aim of the study is to identify the possible antileishmanicidal activity target(s) of N¹,N⁴-[dibenzylbutane-4',4''-(dioxymethylenebenzene)]-1,4-diamine from plethora of pathways in kinetoplastids. The compound was docked using AutoDockTools-1.5.6 against 8 co-crystallized proteins selected from the protein data bank and representing important biosynthetic pathways. The results showed that the N, N'-substituted diamine binds more efficiently to the glyceraldehyde-3-phosphate dehydrogenase, GPDH (E = -8.97 Kcal/mol and K_i = 0.267 µM; K_i co-crystallized ligand = 19.39 µM) which is responsible for the conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate, and pteridine reductase I, PTR1 (E = -8.75 Kcal/mol and K_i = 0.387 µM; K_i co-crystallized ligand = 60.56 µM) which reduces both pterins and folates to tetrahydrobiopterin and tetrahydrofolate respectively. Moderate binding activity by the ligand was obtained for the protein kinases, CDKs (E = -8.37 Kcal/mol and K_i = 0.729 µM; K_i co-crystallized ligand = 26.80 µM) and trypanothione reductase, TR (E = -8.57 Kcal/mol and K_i = 0.525 µM; K_i co-crystallized ligand = 174.68 µM) of the trypanothione biosynthetic pathway. With E > -7.35 Kcal/mol and K_i > 4.10 µM, the ligand appears to have no significant inhibition of the squalene synthase (SQS), lactoyl glutathione lyase (LGL) and pteridine synthase (TS) of the sterol, glyoxalase and trypanothione biosynthetic pathways. In conclusion, the efficient inhibition of GPDH and PTR1 targets in Leishmania by N, N-substituted diamine molecule provides more insights into understanding the mechanism of leishmanicidal activity.