A robust method for measuring aminoacylation through tRNA-Seq.

Current methods to quantify the fraction of aminoacylated tRNAs, also known as the tRNA charge, are limited by issues with either low throughput, precision, and/or accuracy. Here, we present an optimized charge transfer RNA sequencing (tRNA-Seq) method that combines previous developments with newly described approaches to establish a protocol for precise and accurate tRNA charge measurements. We verify that this protocol provides robust quantification of tRNA aminoacylation and we provide an end-to-end method that scales to hundreds of samples including software for data processing. Additionally, we show that this method supports measurements of relative tRNA expression levels and can be used to infer tRNA modifications through reverse transcription misincorporations, thereby supporting multipurpose applications in tRNA biology.

An anticodon-sensing T-boxzyme generates the elongator nonproteinogenic aminoacyl-tRNA in situ of a custom-made translation system for incorporation.

In the hypothetical RNA world, ribozymes could have acted as modern aminoacyl-tRNA synthetases (ARSs) to charge tRNAs, thus giving rise to the peptide synthesis along with the evolution of a primitive translation apparatus. We previously reported a T-boxzyme, Tx2.1, which selectively charges initiator tRNA with N-biotinyl-phenylalanine (BioPhe) in situ in a Flexible In-vitro Translation (FIT) system to produce BioPhe-initiating peptides. Here, we performed in vitro selection of elongation-capable T-boxzymes (elT-boxzymes), using para-azido-l-phenylalanine (PheAZ) as an acyl-donor. We implemented a new strategy to enrich elT-boxzyme-tRNA conjugates that self-aminoacylated on the 3'-terminus selectively. One of them, elT32, can charge PheAZ onto tRNA in trans in response to its cognate anticodon. Further evolution of elT32 resulted in elT49, with enhanced aminoacylation activity. We have demonstrated the translation of a PheAZ-containing peptide in an elT-boxzyme-integrated FIT system, revealing that elT-boxzymes are able to generate the PheAZ-tRNA in response to the cognate anticodon in situ of a custom-made translation system. This study, together with Tx2.1, illustrates a scenario where a series of ribozymes could have overseen aminoacylation and co-evolved with a primitive RNA-based translation system.

Ajo y riesgo cardiovascular / Garlic and cardiovascular risk

El ajo es una de las plantas curativas más antiguas de la que tenemos referencia. En el presente trabajo, revisaremos las evidencias existentes sobre el consumo de ajo y el riesgo cardiovascular, analizando su papel sobre el perfil lipídico, el endotelio vascular y la agregación plaquetaria. El consumo regular de 5 g de ajo crudo dos veces al día durante 42 días disminuye los niveles de colesterol total y triglicéridos, no obstante la mayor parte de los estudios realizados en el campo de los lípidos han sido llevados a cabo en animales. En modelos animales (perros y ratas) se ha demostrado los efectos hipotensores del ajo de manera dosis dependiente. Algunos trabajos han demostrado que el ajo activa la fibrinolisis, además de suprimir el sistema de coagulación previniendo así la formación de trombos. Estos resultados se han corroborado en otro trabajo, en el cual se demuestra que el extracto alcohólico de ajo es un potente inhibidor de la agregación plaquetaria. En resumen, los efectos del ajo sobre la disminución del riesgo cardiovascular son importantes. No obstante los estudios en humanos son escasos y todavía falta por demostrar que estos efectos disminuyan los eventos cardiovasculares así como la cantidad necesaria de ajo para obtener estos beneficios

Garlic is one of the oldest dietary vegetables. In this article, we´ll review the evidences of cardiovascular risk factors and garlic consumption, analizing the influence on lipid levels, vascular endothelium and platelet aggregation. Regular consumption of 5 g (raw garlic) twice per day during 42 days decreases levels of cholesterol and triglyceride. However, almost all lipid studies have been realized in animals. In animal models (dogs and rats), it has been demonstrated a dose depending hypotensive effect, too. Garlic consumption has demonstrated an activation of fibrinolisis and a down regulation of coagulation, with a decrease in the rate of thrombogenesis. These results have been repeated by otherwork, in which a garlic alcoholic extract is a potent inhibitor of platelet aggregation. In summary, the effects of garlic on cardiovascular risk are important. However, it is necessary to demonstrate a decrease on cardiovascular events and to elucidate the amount of garlic to obtain benefict effects, most studies are necessary

Regulation, characterization and factors affecting the amino acid transport systems

En esta revisión se describen los diferentes sistemas de transporte para aminoácidos, la caracterización de éstos y de sus componentes, los factores que afectan las características cinéticas de los acarreadores específicos de los sistemas de transporte, y la importancia del transporte de aminoácidos en el mantenimiento de las concentraciones plasmáticas e intracelulares de aminoácidos en diversos tejidos, así como su papel en el control del metabolismo de aminoácidos.

Lysine turnover in man measured by intravenous infusion of L-[U-14C] lysine

Lysine turnover was measured in three adult subjects by intravenous infusion of L-[U-14C]lysine for periods of 27-30 hours. A plateau specific activity of free lysine was reached in the plasma after c. 12 hours. The total turnover rates, calculated in terms of g protein.kg body weight-1 day-1 were 1.56 in an adult aged 50, 3.24 and 3.07 in two young men 19 years old. The results are discussed in relation to previous measurements of total amino acid turnover in man made by different methods. They fall within the range found by the methods which are theoretically the most satisfactory. (AU)