Caracterização das proteínas LmxM.36.6760 e LinJ.30.3360 de função desconhecida em diferentes espécies de Leishmania

Abstract

Leishmaniasis is a disease caused by trypanosomatid protozoa of the genus Leishmania, and in Brazil the species Leishmania amazonensis and Leishmania braziliensis are predominantly associated with American Cutaneous Leishmaniasis (ACL) while Leishmania infantum is an agent of Visceral Leishmaniasis (VL). These species were used in this study because of their clinical and epidemiological importance in our country. Sequencing the genome of some Leishmania species has shown that each genome can contain about 8,000 genes encoding proteins, of which more than half are hypothetical genes. Despite this large number, there are few data on hypothetical proteins and their biological functions, and studies for characterization are indispensable. In a previous study of our group, a comparative proteomic analysis was performed between L. infantum strains with virulence difference. Among proteins with difference in abundance, proteins of unknown function LmxM.36.6760, which increased in the most virulent strain, and LinJ.30.3360, which increased in the less virulent strain, were selected. Thus, in the present study, it was our aim to characterize these two proteins of unknown function. Initially, we used bioinformatics analysis through the serves NCBI, ProtParam, UniProtKB, Expasy which indicated the presence of sequences similar to those of LmxM.36.6760 and LinJ.30.3360 in L. braziliensis, L. donovani, L. major, L. mexicana and L. infantum, and these do not present signal peptide, transmembrane domain or GPI anchor. The secondary structure predicted for LmxM.36.6760 is alpha-helix whereas for LinJ.30.3360 protein is beta-pleated. We observed similarity in the results obtained among the three cell localization predictors: TargetP, WOLF PSORT and DeepLoc-1.0, which indicated localization in the mitochondria for LmxM.36.6760 protein and localization in the cytoplasm of the parasite for protein LinJ.30.3360. Confocal microscopy results were inconclusive as to the cellular localization of LmxM.36.6760 and LinJ.30.3360 proteins. It was possible to observe that both proteins present similar abundance among the species L. amazonensis, L. braziliensis and L. infantum.