Authors

Discussion

Leishmania donovani is the causative organism of visceral leishmaniasis. We have identified an enzyme in L. donovani known as a galactokinase-like protein (LdGalK), which could be a novel target for drug development. In the human host, two GalK paralogues are expressed, GalK1 and GalK2, which metabolise galactose in the Leloir pathway and N-acetyl galactosamine pathway, respectively. Both kinases instigate the first committed step in their respective pathways and phosphorylate the carbon-1 position in their carbohydrate ligand.

We have expressed recombinant LdGalK in E. coli and purified the protein to high purity and yield. The recombinant enzyme is catalytically active with a substate affinity to galactose in the low micromolar range. Interestingly, size exclusion chromatography of LdGalK suggests either an open/closed conformation of the enzyme or dimerization. Future research will test potential inhibitors against recombinant LdGalK in vitro and against L. donovani parasites in vivo.