The intracellular parasite Trypanosoma cruzi is the aetiological agent of Chagas disease, a public health concern with an increasing incidence rate. This increase is due, among other reasons, to the parasite’s drug resistance mechanisms, which require nicotinamide adenine dinucleotide (NAD+). Furthermore, this molecule is involved in metabolic and intracellular signalling processes necessary for the survival of T. cruzi throughout its life cycle. NAD+ biosynthesis is performed by de novo and salvage pathways, which converge on the step that is catalysed by the enzyme nicotinamide mononucleotide adenylyltransferase (NMNAT) (enzyme commission number: 2.7.7.1). The identification of the NMNAT of T. cruzi is important for the development of future therapeutic strategies to treat Chagas disease. In this study, a hypothetical open reading frame (ORF) for NMNAT was identified in the genome of T. cruzi. The corresponding putative protein was analysed by simulating structural models. The ORF was amplified from genomic DNA by polymerase chain reaction and was further used for the construction of a corresponding recombinant expression vector. The expressed recombinant protein was partially purified and its activity was evaluated using enzymatic assays. These results comprise the first identification of an NMNAT in T. cruzi using bioinformatics and experimental tools and hence represent the first step to understanding NAD+ metabolism in these parasites.

Leishmania braziliensis es un parásito protozoario causante de la mayor parte de casos de leishmaniasis cutánea en al menos quince países del continente americano. La Organización Mundial de la Salud (OMS) ha reportado que cerca de doce millones de personas están infectadas en el mundo y que este número aumenta cada año. Debido al delicado problema de salud pública derivado de la prevalencia de esta enfermedad se hace necesario el estudio del metabolismo de este parásito. En tal sentido se ha estudiado la proteína NMNAT de este parásito, la cual es una enzima central del metabolismo de todos los organismos al estar encargada de la síntesis del NAD+, un importante cofactor en reacciones redox de procesos centrales del metabolismo celular. En la NMNAT de L. braziliensis se ha encontrado una secuencia de 44 aminoácidos en el extremo N-terminal carente de homología con la proteína del hospedero. En este estudio se produjeron anticuerpos IgG específicos contra esta secuencia, utilizando como antígenos péptidos que contuvieran la secuencia mencionada. Los anticuerpos obtenidos mostraron un reconocimiento de la NMNAT recombinante de L. braziliensis mediante ensayo por western blot.

Leishmania braziliensis is a protozoan which is cause of the most of the cutaneous leishmaniasis cases in at least 15 countries from America. World Health Organization (WHO) has reported that around 12 millions of people are infected in the world and this number increase every year. Because of the delicate problem of public health due to the prevalence of this disease, it is necessary the metabolism study in this parasite. In this way has been studied NMNAT protein of the parasite, which is a central enzyme of the metabolism of all organisms, since it is in charge of synthesizing NAD+, an important cofactor in oxidation-reduction reactions of central processes in the cellular metabolism. In The NMNAT of L. has been found a 43 amino acids sequence in the N terminal, which does not have homology with the protein in the human host. In this study were produced IgG antibodies against this sequence, using like antigens peptides that had the mentioned sequence. The produced antibodies recognized the recombinant NMNAT of L. braziliensis through western blot assay.

Leishmania braziliensis é um parasita protozoário que causa a maioria dos casos de leishmaniose cutânea em pelo menos 15 países das Américas. A Organização Mundial de Saúde (OMS) informou que cerca de 12 milhões de pessoas estão infectadas em todo o mundo e esse número aumenta a cada ano. Devido ao delicado problema de saúde pública decorrentes da prevalência desta doença é necessário estudar o metabolismo do parasita. A este respeito temos estudado a proteína NMNAT deste parasita, que é uma enzima central no metabolismo de todos os organismos de estar envolvido na produção de NAD+, um importante cofator em reações redox de processos centrais de celulares metabolismo. No L. braziliensis NMNAT encontrou uma seqüencia de 43 aminoácidos no terminal N homologia com a proteína faltando host. Este estudo produziu anticorpos IgG específicos para esta seqüência, usando como peptídeos de antígeno contendo a seqüência mencionada. Os anticorpos obtidos mostraram um reconhecimento da NMNAT L. braziliensis recombinantes por meio de julgamento por western blot.