Utilização da enzima β-cetoacil ACP redutase (OAR) da via FAS II de Plasmodium falciparum como um alvo para busca de novos compostos antimaláricos.

Abstract

Malaria is a parasitic disease with the highest number of hospitalizations and deaths each year worldwide, one of the major public health problems in Africa, South America and East Asia. According to estimates by the World Health Organization, 198 million people became ill in 2014. This evidence led to the development of new strategies for the treatment of malaria in order to minimize the growing problem of parasite resistance to commonly used medicinal products. With the elucidation of metabolic pathways essential for some of the malaria parasite development, new molecular targets have been proposed for the development of new drugs, among which can be cited Hypoxanthine Guanine Phosphoribosyltransferase (HGPRT) Chorismate synthase, enoyl-ACP reductase and purine nucleoside phosphorylase (PNP). Objective: The objective of this study was the identification of compounds as potential inhibitors of beta-ketoacyl-ACP reductase enzyme - OAR Plasmodium falciparum. Results: The 28kDa enzyme was expressed in Escherichia coli and purified by affinity chromatography. Searches of new molecules through Sceenning by Virtual Docking were able to find 30 molecules of which was selected Skyrin molecule due to its higher affinity for the enzyme OAR. Analysis of enzyme activity by spectrophotometry using NADPH and acetoacetyl-CoA substrates the enzyme showed activity OAR reducing NADPH in the various substrates concentrations, and was shown to be inhibited by Skyrin. It was also possible to show by surface plasmon resonance (SPR) Skyrin that the molecule binds to the enzyme OAR but dissociates easily.In tests using cell cultures infected with P. falciparum this molecule showed antimalarial activity with IC50 8,88μg / ml, and is not toxic to HepG2 cell line. Conclusion:This new approach has significant advantages compared to traditional methods, since it establishes in advance the specific bioactive and its mechanism of action. Ideal targets for the development of antimalarial drugs against infectious agents must be essential to the survival of the pathogen and the host is absent.