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The importance of parasitic peptidases in the supply of amino acids in promastigotes of Leishmania (leishmania) infantum

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Author(s):
Thiago Fidelis Ferrão
Total Authors: 1
Document type: Master's Dissertation
Press: São Paulo.
Institution: Faculdade de Medicina (FM/SBD)
Defense date:
Examining board members:
Heitor Franco de Andrade Junior; Selma Giorgio; Roberto Mitsuyoshi Hiramoto; Patrick Jack Spencer
Advisor: Heitor Franco de Andrade Junior
Abstract

Visceral leishmaniasis (VL) is a disease widely distributed in Brazil and worldwide, with high morbidity and mortality. In Brazil, it is caused by the species Leishmania (L.) infantum with vector transmission by females of Lutzomyia longipalpis. The parasite has two forms in its life cycle, the promastigotes present in insect vectors and amastigotes present in mammalian cells. The parasite\'s nutrition depends on amino acids obtained by interactions with the host. Different peptidases have already been documented in the Leishmania parasites, with four groups according to the active site. In this work, we evaluate the role of parasitic peptidases in nutritional processes, survival and multiplication promastigotes of L. (L.) infantum. Promastigotes were grown in standard medium (MP199). The number of parasites was monitored daily and on the 3rd day of stay in culture medium the parasites were analyzed in relation to its composition. The data obtained were used as a reference to standardize the analytical techniques used later in the parasites, captured by means rich in free amino acids (MRA) and rich in protein (MRP) and their culture supernatants. The comparison between parasites maintained in MRA and MRP demonstrates a higher protein concentration in MRP 26.22 Micro Grama / mL compared to MRA 10.71 Micro Grama / mL. As the morphological changes show a greater thickening of glycocalyx in promastigotes with greater proteolytic activity applied to MRP, detected with protein substrates marked with fluorochrome FITC. The data suggested here as parasitic peptidases present nutritional activities and methods that cause effects on their composition and cause parasitic changes inducing the actions of peptidases and modifications of the parasite surface to allow greater ease of use of the molecules and samples of amino acids, a different way from The function of these enzymes allows a better understanding of parasitic metabolism and its availability as a target for new drugs (AU)

FAPESP's process: 16/15738-3 - The importance of proteases provision essential amino acids sources in Leishmania (Leishmania) infantum promastigotes
Grantee:Thiago Fidelis Ferrão
Support Opportunities: Scholarships in Brazil - Master