GASTROINTESTINAL DIGESTION OF KAHAI PROTEIN CONCENTRATE (CARYODENDRON ORINOCENSE KARST)

Objective: The aim of this study was to obtain kahai protein concentrate from Caryodendron orinocense karst cultivated in the region Amazonia of Ecuador and characterizes its gastric and duodenal hydrolysates using the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis method and the reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) method.Methods: Kahai seeds (C. orinocense karst) were utilized to obtain kahai protein concentrate at pH 5.0 using the isoelectric precipitation method and then subject to gastric hydrolysis with pepsin enzyme (2000 U/mg of protein) at pH 1.2, pH 2.0, and pH 3.2 at 37°C for 2 h with agitation in simulated gastric fluids and then to duodenal hydrolysis with pancreatin (mix enzymes) at pH 7.0 at 37°C for 3 h with agitation in simulated intestinal fluid. Gastric and duodenal hydrolysates from kahai were characterized using the SDS-PAGE electrophoresis method and the RP-UHPLC chromatography method.Results: Proteins obtained from kahai (C. orinocense karst) were hydrolyzed with pepsin, only one protein with molecular weight of 100 kDa presented resistance to hydrolysis with pepsin at all pHs assayed. All proteins from kahai protein concentrate were totally hydrolyzed with pancreatin in in vitro conditions.Conclusion: This study suggests that kahai protein concentrates have a high grade of digestibility in vitro when using the gastroduodenal model of digestion. Kahai protein can be a good source of alternative vegetal proteins to be consumed by animals and humans

Protein repeats evolve and emerge in giant viruses

Nucleocytoplasmatic large DNA viruses (NCLDVs or giant viruses) stand out because of their relatively large genomes encoding hundreds of proteins. These species give us an unprecedented opportunity to study the emergence and evolution of repeats in protein sequences. On the one hand, as viruses, these species have a restricted set of functions, which can help us better define the functional landscape of repeats. On the other hand, given the particular use of the genetic machinery of the host, it is worth asking whether this allows the variations of genetic material that lead to repeats in non-viral species. To support research in the characterization of repeat protein evolution and function, we present here an analysis focused on the repeat proteins of giant viruses, namely tandem repeats (TRs), short repeats (SRs), and homorepeats (polyX). Proteins with large and short repeats are not very frequent in non-eukaryotic organisms because of the difficulties that their folding may entail; however, their presence in giant viruses remarks their advantage for performance in the protein environment of the eukaryotic host. The heterogeneous content of these TRs, SRs and polyX in some viruses hints at diverse needs. Comparisons to homologs suggest that the mechanisms that generate these repeats are extensively used by some of these viruses, but also their capacity to adopt genes with repeats. Giant viruses could be very good models for the study of the emergence and evolution of protein repeats.Fil: Erdozain, Sofía. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Ciencias Biológicas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Barrionuevo, Emilia Mercedes. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Ripoll, Lucas. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ingeniería Genética y Biología Molecular y Celular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mier, Pablo. Johannes Gutenberg Universitat Mainz; AlemaniaFil: Andrade Navarro, Miguel A.. Johannes Gutenberg Universitat Mainz; Alemani

Erratum to: Journal of Computational Neuroscience, DOI 10.1007/s10827-010-0303-y and DOI 10.1007/s10827-010-0304-x

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Influencia de algunos fármacos tranquilizantes sobre el aprovechamiento nutritivo de proteínas y grasas en la rata

Se estudia en ratas el aprovechamiento nutritivo de la proteína y grasa, bajo la influencia de agentes tranquilizantes (Diazepan y Perfenacina) adicionados a la dieta a dos niveles (1,5 mg/100 g de dieta y 3 mg/100 g de dieta) encontrando los siguientes resultados. 1) La dieta adicionada de la dosis mínÍma de Diazepan no modifica la ingesta, cambios ponderales, eficacia digestiva ni metabólica del nitrógeno, tanto en hembras como en machos. A dosis superiores el Diazepan tampoco modifica de una manera patente ninguno de los parámetros anteriormente citados, si bien tienden a ser mayores. 2) La eficacia digestiva de la grasa no se modifica por el efecto del Diazepan adicionado a la dosis mínima; sin embargo, la dosis de 3 mg/100 g de dieta disminuye el coeficiente de digestibilidad lipídico, descenso que es mucho más patente en hembras que en machos. 3) La Perfenacina disminuye la in gesta de alimentos, sobre todo en machos, y a la dosis máxima. No obstante, la eficacia digestiva del nitrógeno, no se modifica. Tampoco afecta la retención de nitrógeno a nivel metabólico en hembras, en tanto que en los machos de lugar a una importante reducción. El fármaco no modifica la eficacia digestiva de la grasa.Nutritive utilization of protein and fat in rats under tratment with tranquilizer agents (Diazepan and Perfenacine) added to diet at two levels 0,5 mg/lOO g and 3 mg/lOO g of diet) was studied. 1) Diet with lowest doses of Diazepan does not modify intake, pon deral changes, digestive or metabolic efficacy of nitrog- en, either in males or in females. Similarly highest doses of Diazepan do not clearly modify none of those parameters, although aH of them showed a mild increase. 2) Digestive efficacy of fat do es not change because of lowest doses of Diazepan, however doses of 3 mg/lOO g of diet do diminish lipidic digestibility coefficient, decrease that is much biger in females than in males. 3) Perfenacine, at higest doses decreases food intake above aH in males. Nevertheles digestive efficacy of nitro gen was not modify, neither nitro gen retention at metabolic levels in females, however in males it was detected a clear reduction in this parameter. This drug do es not modify digestive efficacy of fat

Ferroelectric Capped Magnetization in Multiferroic PZT/LSMO Tunnel Junctions

Self-poled ultra-thin ferroelectric PbZr0.52Ti0.48O3 (PZT) (5 and 7 nm) films have been grown by pulsed laser deposition technique on ferromagnetic La0.67Sr0.33MnO3 (LSMO) (30 nm) to check the effect of polar capping on magnetization for ferroelectric tunnel junction (FTJ) devices. PZT/LSMO heterostructures with thick polar PZT (7 nm) capping show nearly 100% enhancement in magnetization compared with thin polar PZT (5 nm) films, probably due to excess hole transfer from the ferroelectric to the ferromagnetic layers. Core-level X-ray photoelectron spectroscopy studies revealed the presence of larger Mn 3s exchange splitting and higher Mn3+/Mn4+ ion ratio in the LMSO with 7 nm polar capping.Comment: 17 pages, 5 figure

Caracterización física y química de ríos de montaña (Tafí del Valle-Tucumán-Argentina)

En este trabajo se estudió durante el ciclo anual 2000-2001, a los ríos Blanquito, Churqui, de La Ovejería, de Las Carreras, Tafí, El Mollar y Los Sosa, ubicados a 2000 msnm en el valle de Tafí (Tucumán-Argentina). El objetivo de esta contribución fue caracterizar e interpretar las variaciones espacio-temporales de los parámetros físicos y químicos en relación con la dinámica hidrológica a la que se encuentran sujetos estos ecosistemas acuáticos y además, comparar la calidad de sus aguas. Las variables físicas y químicas analizadas fueron: oxígeno disuelto (OD), demanda bioquímica de oxígeno (DBO5), iones mayoritarios, compuestos nitrogenados, ortofosfatos y metales pesados. Los resultados muestran que la temperatura varió entre 4.2 y 28 ◦C, el pH fluctuó de neutro a alcalino (6.7-8.7) y la conductividad eléctrica entre 64 y 296 μS/cm. El OD y la DBO5 se mostraron estables, alcanzando máximos valores de 10.1 y 2 mg/l, respectivamente. El agua pudo caracterizarse como bicarbonatada-cálcica dominante. Las concentraciones de N-NO−3 oscilaron entre 0.1 y 0.6 mg/l, el N-NO−2 sólo llegó en el río Churqui a 0.01 mg/l y el N-NH+4 alcanzó valores de 0.8 mg/l. En general los registros de los ortofosfatos fueron inferiores a 0.2 mg/l. Los metales pesados Cu2+ y Fe3+ llegaron a un máximo de 3 mg/l y 1.8 mg/l, respectivamente. Las mayores concentraciones del hierro se presentaron en el río de La Ovejería y de cobre en el río El Mollar, probablemente por contaminación antropogénica. La interpretación de los análisis de componentes principales realizados sobre la matriz de parámetros físicos y químicos, permitió diferenciar a los sistemas lóticos temporal y espacialmente. El componente 1 ordenó a los ríos de acuerdo a los iones mayoritarios predominantes y a la conductividad, lo que podría interpretarse como un eje de mineralización. Los componentes 2 y 3, ordenaron las muestras de invierno y primavera y las de verano y otoño, de acuerdo a la variación cíclica estacional coincidiendo con las condiciones climáticas del área de estudio.In this work, throughout the 2000-2001 annual period, the Blanquito, Churqui, de La Ovejería, de Las Carreras, Tafí, El Mollar and Los Sosa rivers, located at 2000 m above sea level in the Taf'ı Valley (Tucumán-Argentina) were studied. The aim of this paper was not only to characterize and understand the spatial and temporal variations of physical and chemical parameters related to the hydrological dynamics these aquatic ecosystems are subject to, but also to compare the quality of their waters. Physical and chemical variables analysed were: dissolved oxygen (DO), biochemical oxygen demand (BOD5), preponderant ions, nitrogenous compounds, orthophosphates, and heavy metals. Results show that the temperature ranged between 4.2 and 28 ◦C, pH fluctuated from neutral to alkaline (6.7-8.7) and electrical conductivity varied between 64 and 296 μS/cm. DO and BOD5 were stable and reached maximum values of 10.1 and 2 mg/l, respectively. The water could be characterized as mainly bicarbonated-calcic. N-NO−3 concentrations ranged between 0.1 and 0.6 mg/l, N-NO−2 reaching only 0.01 mg/l in the Churqui river, and N-NH+4 reached values of 0.8 mg/l. In general, orthophosphate records were lower than 0.2 mg/l. Maximum values for heavy metals, Cu2 + and Fe3 + were 3 mg/l y 1.8 mg/l, respectively. Iron highest concentrations were found in de La Ovejería river, whereas those for copper were found in El Mollar river, probably due to anthropogenic pollution. The interpretation of the main component analyses carried out on the physical and chemical parameters matrix, allowed to differentiate lotic systems both temporally and spatially. Component 1 ordered the rivers according to both the prevailing ions and conductivity, which could be interpreted as a mineralization axis. Components 2 and 3 ordered the winter and spring, and the summer and autumn samples according to the seasonal cyclic variation, coinciding with the climatic conditions of the area under study