A Mechanistic Probe into the Dual Inhibition of T. cruzi Glucokinase and Hexokinase in Chagas Disease Treatment – A Stone Killing Two Birds?

Abstract

Glucokinase (GLK) and Hexokinase (HK) have been characterized as essential targets in Trypanosoma cruzi (Tc)‐mediated infection. A recent study reported the propensity of the concomitant inhibition of TcGLK and TcHK by compounds GLK2‐003 and GLK2‐004, thereby presenting an efficient approach in Chagas disease treatment. We investigated this possibility using atomic and molecular scaling methods. Sequence alignment of TcGLK and TcHK revealed that both proteins shared approximately 33.3 % homology in their glucose/inhibitor binding sites. The total binding free energies of GLK2‐003 and GLK2‐004 were favorable in both proteins. PRO92 and THR185 were pivotal to the binding and stabilization of the ligands in TcGLK, likewise their conserved counterparts, PRO163 and THR237 in TcHK. Both compounds also induced a similar pattern of perturbations in both TcGLK and TcHK secondary structure. Findings from this study therefore provide insights into the underlying mechanisms of dual inhibition exhibited by the compounds. These results can pave way to discover and optimize novel dual Tc inhibitors with favorable pharmacokinetics properties eventuating in the mitigation of Chagas disease.

Discovery of Strong 3-Nitro-2-Phenyl-2H-Chromene Analogues as Antitrypanosomal Agents and Inhibitors of Trypanosoma cruzi Glucokinase

“…We arrive to this conclusion since it is already known that T. brucei hexokinase I is a validated therapeutic drug target [36] and the T. brucei hexokinase isoenzymes most likely share a high degree of three-dimensional structural similarity to TcHxK. Moreover, the virtual three-dimensional structural work by Omolabi and colleagues, in which they contended a theoretical binding site for two 3-nitro-2-phenyl-2H-chromene analogues on TcHxK [30], seems reasonable. However, we believe that in order to move forward, their computational work should be investigated experimentally to validate their binding site hypothesis.…”

“…For the TcGlcK binding site, they showed that compounds 1 (GLK2-003) and 9 (GLK2-004) had an affinity to interact with residues P92 and T185, which were found near the D-glucose binding site, as visualized in the solved X-ray crystal structure of TcGlcK first reported by Cordeiro and colleagues [33]. They also pointed out that in TcHxK, residues of interest were P163 and T237, which were also found near the D-glucose binding site [30]. Compounds 1 and 9 would be considered as competitive inhibitors in this case; however, our study showed a different outcome.…”

“…Although, compounds 5 and 7 lacked the necessary strong binding affinity for TcGlcK. Observing this enhanced growth inhibition against T. brucei is justified, since Chambers and colleagues determined that T. brucei hexokinase 1 Regarding the 3-nitro-2-phenyl-2H-chromene class of compounds inhibiting the T. cruzi glucose kinases, Omolabi and colleagues reported on a computational investigation where they predicted the ligand-binding sites in TcGlcK and TcHxK [30]. For the TcGlcK binding site, they showed that compounds 1 (GLK2-003) and 9 (GLK2-004) had an affinity to interact with residues P92 and T185, which were found near the D-glucose binding site, as visualized in the solved X-ray crystal structure of TcGlcK first reported by Cordeiro and colleagues [33].…”

“…Moreover, this finding has increased our interest in exploring the inhibitory activity of commercially available 3-nitro-2-phenyl-2H-chromene compounds against TcGlcK and T. cruzi parasites co-cultured in mammalian cells. With the highly plausible postulation about the mechanism of simultaneous inhibition of TcGlcK and TcHxK by the 3-nitro-2-phenyl-2H-chromene compound class [17,30], we were eager to learn of any observable trends in this regard. We were also interested in learning if these compounds would impart a growth inhibitory effect on T. brucei, the etiological agent of human African trypanosomiasis [31].…”