NMR structure and dynamics of Q4DY78, a conserved kinetoplasid-specific protein from Trypanosoma cruzi.

The 106-residue protein Q4DY78 (UniProt accession number) from Trypanosoma cruzi is highly conserved in the related kinetoplastid pathogens Trypanosoma brucei and Leishmania major. Given the essentiality of its orthologue in T. brucei, the high sequence conservation with other trypanosomatid proteins, and the low sequence similarity with mammalian proteins, Q4DY78 is an attractive protein for structural characterization. Here, we solved the structure of Q4DY78 by solution NMR and evaluated its backbone dynamics. Q4DY78 is composed of five α -helices and a small, two-stranded antiparallel ß-sheet. The backbone RMSD is 0.22 ± 0.05 Å for the representative ensemble of the 20 lowest-energy structures. Q4DY78 is overall rigid, except for N-terminal residues (V8 to I10), residues at loop 4 (K57 to G65) and residues at the C-terminus (F89 to F112). Q4DY78 has a short motif FPCAP that could potentially mediate interactions with the host cytoskeleton via interaction with EVH1 (Drosophila Enabled (Ena)/Vasodilator-stimulated phosphoprotein (VASP) homology 1) domains. Albeit Q4DY78 lacks calcium-binding motifs, its fold resembles that of eukaryotic calcium-binding proteins such as calcitracin, calmodulin, and polcacin Bet V4. We characterized this novel protein with a calcium binding fold without the capacity to bind calcium.

Crystal structure of Q4D6Q6, a conserved kinetoplastid-specific protein from Trypanosoma cruzi.

Complete genome sequencing of the kinetoplastid protozoans Trypanosoma cruzi, Trypanosoma brucei and Leishmania major (Tritryp), published in 2005, opened up new perspectives for drug development targeting Chagas disease, African sleeping sickness and Leishmaniasis, neglected diseases affecting millions of most economically disadvantaged people. Still, half of the Tritryp genes code for proteins of unknown function. Moreover, almost 50% of conserved eukaryotic protein domains are missing in the Tritryp genomes. This suggests that functional and structural characterization of proteins of unknown function could reveal novel protein folds used by the trypanosomes for common cellular processes. Furthermore, proteins without homologous counterparts in humans may provide potential targets for therapeutic intervention. Here we describe the crystal structure of the T. cruzi protein Q4D6Q6, a conserved and kinetoplastid-specific protein essential for cell viability. Q4D6Q6 is a representative of a family of 20 orthologs, all annotated as proteins of unknown function. Q4D6Q6 monomers adopt a ßßαßßαßß topology and form a propeller-like tetramer. Oligomerization was verified in solution using NMR, SAXS, analytical ultra-centrifugation and gel filtration chromatography. A rigorous search for similar structures using the DALI server revealed similarities with propeller-like structures of several different functions. Although a Q4D6Q6 function could not be inferred from such structural comparisons, the presence of an oxidized cysteine at position 69, part of a cluster with phosphorylated serines and hydrophobic residues, identifies a highly reactive site and suggests a role of this cysteine as a nucleophile in a post-translational modification reaction.

Chemical shift assignments and secondary structure prediction for Q4DY78, a conserved kinetoplastid-specific protein from Trypanosoma cruzi.

Trypanosoma cruzi, Trypanosma brucei and Leishmania spp. are kinetoplastid protozoa causative agents of Chagas disease, sleeping sickness and leishmaniasis, respectively, neglected tropical diseases estimated to infect millions of people worldwide. Their genome sequencing has revealed approximately 50 % of genes encoding hypothetical proteins of unknown function, opening possibilities for novel target identification and drug discovery. Q4DY78 is a putative essential protein from T. cruzi conserved in the related kinetoplastids and divergent from mammalian host proteins. Here we report the (1)H, (15)N, and (13)C chemical shift assignments and secondary structure analysis of the Q4DY78 protein as basis for NMR structure determination, functional analysis and drug screening.

Automedicação entre graduandos de enfermagem, farmácia e odontologia da Universidade Federal de Alfenas / Self-medication among undergraduation of nursing, pharmacy and odontology of University Federal of Alfenas / Automedicación entre los graduandos de enfermaría, farmacia y odontologia de la Universidad Federal de Alfenas

Estudo cujo objetivo é avaliar o índice de automedicação entre os graduandos do primeiro e do sétimo período dos cursos de Enfermagem, Farmácia e Odontologia da Universidade Federal Alfenas (UNIFAL-MG). Os dados foram adquiridos por meio de um questionário estruturado e semi-estruturado. A amostra foi composta de 245 graduandos dos referidos cursos, de uma população total de 280. Os dados sofreram tratamento estatístico pelo teste de Qui-quadrado. O índice de automedicação foi de 222 (90,6%). A principal queixa que levou à automedicação foi dor de cabeça e o medicamento mais utilizado foi a Dipirona. Houve diferenças significativas quanto à intensificação da prática da automedicação quando comparados o primeiro e o sétimo período.

The purpose of this study was to evaluate the level of self-medication by undergraduate students in the first and seventh semesters in the courses of Nursing, Pharmacy and Dentistry at the Federal University of Alfenas. Data was collected through a structured and semi-structured questionnaire. The sample was made up of 245 undergraduates from the various courses, out of a total population of 280. The data underwent statistical treatment by the Qui-squared test. The self-medication rate was of 222 (90,6%). The main complaint that led to self-medication was headache and the most widely used medication was Dipirona (sodic metamizol). There were significant differences in the intensity of the practice of self-medication between the first and seventh semesters.

El objeto del presente estudio ha sido observar el índice de la automedicación entre los estudiantes del primero y del séptimo semestre de los cursos de Enfermería, Farmacia y Odontología de la Universidad Federal de Alfenas ­ UNIFAL-MG. Los datos se obtuvieron a través de cuestionario estructurado y semiestructurado. De un total de 280 estudiantes 245 participaron del muestreo. Los datos tuvieron tratamiento estadístico de la prueba Chi-cuadrado. El índice de automedicación fue del 90,6% (222). La queja principal que llevó a la automedicación fue dolor de cabeza y el medicamento más usado dipirona. Hubo diferencias en cuanto a la intensificación de la práctica de automedicación al comparar los primeros y séptimos semestres.