Functional characterization of hexose transporter 1.

is the most widely distributed human malaria parasite. The eradication of vivax malaria remains challenging due to transmission of drug-resistant parasite and dormant liver form. Consequently, anti-malarial drugs with novel mechanisms of action are urgently demanded. Glucose uptake blocking strategy is suggested as a novel mode of action that leads to selective starvation in various species of malaria parasites. The role of hexose transporter 1 in species is glucose uptake, and its blocking strategies proved to successfully induce selective starvation. However, there is limited information on the glucose uptake properties via hexose transporter 1 (PvHT1). Thus, we focused on the PvHT1 to precisely identify its properties of glucose uptake. The PvHT1 North Korean strain (PvHT1) expressed oocytes mediating the transport of [H] deoxy-D-glucose (ddGlu) in an expression and incubation time-dependent manner without sodium dependency. Moreover, the PvHT1 showed no exchange mode of glucose in efflux experiments and concentration-dependent results showed saturable kinetics following the Michaelis-Menten equation. Non-linear regression analysis revealed a Km value of 294.1 μM and a Vmax value of 1,060 pmol/oocyte/hr, and inhibition experiments showed a strong inhibitory effect by glucose, mannose, and ddGlu. Additionally, weak inhibition was observed with fructose and galactose. Comparison of amino acid sequence and tertiary structure between and HT1 revealed a completely conserved residue in glucose binding pocket. This result supported that the glucose uptake properties are similar to , and PfHT1 inhibitor (compound 3361) works in . These findings provide properties of glucose uptake via PvHT1 for carbohydrate metabolism and support the approaches to vivax malaria drug development strategy targeting the PvHT1 for starving of the parasite.