Characterization of the First Secreted Sorting Nexin Identified in the Protists.

Proteins of the sorting nexin (SNX) family present a modular structural architecture with a phox homology (PX) phosphoinositide (PI)-binding domain and additional PX structural domains, conferring to them a wide variety of vital eukaryotic cell's functions, from signal transduction to membrane deformation and cargo binding. Although SNXs are well studied in human and yeasts, they are poorly investigated in protists. Herein, is presented the characterization of the first SNX identified in protozoan parasites encoded by the BPK_352470 gene.

The Gene Encodes for an Atypical Dual Specificity Lipid-Like Phosphatase Expressed in Promastigotes and Amastigotes; Substrate Specificity, Intracellular Localizations, and Putative Role(s).

The intracellular protozoan parasites of the genus are responsible for Leishmaniases, vector borne diseases with a wide range of clinical manifestations. causes visceral leishmaniasis (kala azar), the most severe of these diseases. Along their biological cycle, parasites undergo distinct developmental transitions including metacyclogenesis and differentiation of metacyclic promastigotes (MPs) to amastigotes.

Measurement of Acid Ecto-phosphatase Activity in Live Parasites.

Acid ecto-phosphatases are enzymes that hydrolyze phosphomonoesters in the acidic pH range with their active sites facing the extacellular medium. Their activities can be measured in living cells. In bacteria and protozoan pathogens, acid ecto-phosphatases have been associated with the survival of intracellular pathogens within phagocytes through inhibition of the respiratory burst, suggesting that they act as virulence factors.

Heterologous expression of the mammalian sodium-nucleobase transporter rSNBT1 in Leishmania tarentolae.

Recombinant expression systems for mammalian membrane transport proteins are often limited by insufficient yields to support structural studies, inadequate post-translational processing and problems related with improper membrane targeting or cytotoxicity. Use of alternative expression systems and optimization of expression/purification protocols are constantly needed. In this work, we explore the applicability of the laboratory strain LEXSY of the ancient eukaryotic microorganism Leishmania tarentolae as a new expression system for mammalian nucleobase permeases of the NAT/NCS2 (Nucleobase-Ascorbate Transporter/Nucleobase-Cation Symporter-2) family.

The Leishmania donovani histidine acid ecto-phosphatase LdMAcP: insight into its structure and function.

Acid ecto-phosphatase activity has been implicated in Leishmania donovani promastigote virulence. In the present study, we report data contributing to the molecular/structural and functional characterization of the L. donovani LdMAcP (L.

New labeled derivatives of the neuroprotective peptide colivelin: synthesis, characterization, and first in vitro and in vivo applications.

Colivelin (CL), first reported in 2005, is the most potent member of the humanin family of neuroprotective peptides with in vitro and in vivo rescuing action against insults associated with Alzheimer's disease (AD). The objective of the present work is the design, synthesis and characterization of specific CL derivatives that can be used as molecular probes in the investigation of the unknown mechanism of CL action. Within this framework, three CL derivatives bearing suitable tags, i.