Development of novel maleimide reagents for protein modification

Chemical methods for protein modification are of utmost importance as they allow the mimicking of post-translational modifications that occur in living cells. In addition, they allow exogenous modifications that are the basis for bioconjugation, protein visualisation (fluorescent tagging) and immobilisation (biotin labelling) and many applications in therapeutics. Bromomaleimides are the first of a new class of reagents that could be efficiently used for the highly selective and reversible modification of cysteine and for the bridging of disulfide bonds in proteins. Aiming to prove that these transformations are not restricted to bromomaleimides, the present work presents a library of novel analogues, bearing different leaving groups on the double bond. By controlling the chemistry of this class of compounds we were able to tune properties such as thiol selectivity, reactivity, water-solubility and cross reactivity with reducing agents. The utility of the novel monosubstitued analogues as protein labelling reagents was shown using a single cysteine mutant of protein Grb2 (L111C) as a model system and a kinetic study was designed with the aim to quantify the difference in reactivity of the various selected analogues. The disubstitued analogues were tested as disulfide bridging reagents using Somatostatin, a 14-aminoacid peptide containing a disulfide bridge. Phenoxymaleimides were shown to be less reactive and to display a different reactivity compared to bromomaleimides. They react with reduced disulfides to form a succinimide bridged product. The successful use of phenoxymaleimides in bridging disulfides in peptides and proteins is described. This strategy is fast and efficient and was optimised as to reduce the risk of disulfide scrambling, protein aggregation and loss of activity, which are the common problems associated with disulfide modification. Also, a novel one-pot protocol for the differentially labelling of disulfides in both peptides and proteins was developed. Several dual modified Somatostatin conjugates were prepared using this strategy

Efecto del peso al sacrificio y de la raza en la calidad instrumental y sensorial de la carne de cabritos lechales

Se utilizaron 141 cabritos de 5 razas españolas a dos pesos de sacrificio y se determinó la calidad instrumental y sensorial de su carne. La influencia del peso al sacrificio es, presumiblemente, muy importante sobre la calidad de la carne, pero este efecto debe ser valorado para cada raza. Aunque la carne del cabrito más ligero tuvo mayores valores en la fuerza de compresión, en el análisis sensorial esta carne fue descrita como más tierna y jugosa

Características de la canal de cabritos de cinco razas españolas

En el presente estudio se han sacrificado 136 cabritos machos de dos niveles de peso para caracterizar de forma conjunta las canales de las razas Blanca Andaluza, Negra Serrana-Castiza, Blanca Celtibérica, Pirenaica y Moncaína. Se han observado diferencias significativas entre todas las razas en las variables de conformación estudiadas excepto en el perímetro de grupa y el índice de compacidad de la canal. La interacción peso-raza fue altamente significativa en las variables engrasamiento y ancho de grupa. EI rendimiento de la canal no fue significativa entre pesos pero si entre razas. En todas las variables con el aumento de peso aumentaron también los valores

Spanish marketing chain for kid’s meat: from breeder to wholesale

Se preguntó a 350 ganaderos de Andalucía, Aragón, Extremadura y castilla-La Mancha y a 350 entradores de Andalucía, Aragón, Madrid, Cataluña y Comunidad Valenciana, acerca de la manera de comprar y vender cabritos o su carne. Las zonas de producción no coinciden con las de comercialización y consumo y existen grandes diferencias entre regiones en cuanto al tamaño de las explotaciones. La distancia más frecuente entre explotación y matadero fue de 300 Km. En general, los ganaderos venden más caro y obtienen mayor margen de ganancia por el cabrito que por el cordero. Los entradores compran y venden más caro el cabrito que el cordero. La carnicería tradicional y la restauración son los destinos mayoritarios de venta de esta carne. La cadena de comercialización se complica cuando interviene una sala de despiece tras el entrador. La forma predominante de venta es la canal entera y cuando es por piezas, la pierna es la pieza más demandada. El consumo es estacional y está asociado a celebraciones. Farmers and wholesalers from different Spanish regions were enquired about the way in which they buy or sale kids or kid’s meat. Productions areas did not match with marketing points. There were great differences between regions in the farms’ size of the farms. The most frequent distance from farm to the slaughterhouse was 300 Km. Farmers sold more expensive and they obtained higher profit margin with kids than with lambs. Wholesalers buy and sold more expensive kid’s meat than lamb. Traditional butchers’ shops and restaurants were the main wholesalers’ customs. Marketing chain became more complex by the intervention of a quartering agent. The main way in which meat was sold was as whole carcasses. When they were sold by pieces, leg was the most demanded one. Kid’s meat presented a seasonal consumption, associated to holidays and celebrations

Effects of whole linseed and rumen-protected conjugated linoleic acid enriched diets on beef quality

Instrumental assessments and sensory tests were performed to evaluate the effects of diet and postmortem ageing time (1, 7 and 21 days) on beef quality. A total of 48 Friesian calves were randomly allocated to four dietary treatments: control, whole linseed (10% linseed), conjugated linoleic acid (CLA) (2% protected CLA), and whole linseed+CLA (10% linseed and 2% protected CLA). Animals were slaughtered at 458±16.6 kg live weight and 11 months of age. Ageing was more significant than diet on most instrumental parameters. Meat from linseed enriched diets had greater drip loss (P=0.001) and intramuscular fat (P=0.01) than meat from animals fed CLA. Beef aged for 7 and 21 days had lower cooking losses (P=0.01) and shear force (P=0.001) than beef aged for 1 day. Lightness was affected only by display time. The addition of CLA in the diet increased hue and yellowness, whereas the inclusion of linseed decreased these values, as well as increased redness. Linseed in the diet decreased fat odour (P=0.05), but increased beef (P=0.01) and liver (P=0.05) flavours. Meat aged for 21 days was significantly more rancid (P=0.001), even under vacuum storage. Several organoleptic properties were improved with the inclusion of linseed in the diet, whereas they remained unaffected by the inclusion of CLA

Effect of production system before the finishing period on carcass, meat and fat qualities of beef

Twenty Gascon young bulls that had been reared either in intensive conditions (INT) (n = 10) with early weaning at 3 to 4 months, or in a traditional extensive (EXT) system (n = 10) with weaning at 7 months, were subjected to the same conditions during the 145-day finishing period. Production system before the finishing period did not affect conformation, dressing percentage or morphology of the carcass; nevertheless, tissue composition differed somewhat between the two groups. Display had a stronger effect on meat colour than did production system. Percentage of myoglobin was highest in INT (P ⩽ 0.001), although meat texture and sensory quality did not differ between rearing conditions. EXT animals had darker, more yellow fat, a higher percentage of n-3 fatty acids (P ⩽ 0.001), a lower percentage of saturated fatty acids (P ⩽ 0.05) and a lower n-6/n-3 index (P ⩽ 0.001) than did the INT-reared animals. Production system before the fattening period might modify some of the characteristics of commercial beef, especially those associated with fat.This research was financed by European Project Programmes POCTEFA-OTRAC I 2009/010. The authors thank the OTRAC consortium members and the local government (DGA) for the PhD scholarship.info:eu-repo/semantics/publishedVersio

Lactancia artificial o natural? 1ª parte: Influencia sobre la calidad de la canal de los cabritos

En las razas caprinas de aptitud lechera, el cabrito es considerado en muchas ocasiones como un subproducto, por lo que frecuentemente se separa de la madre y se alimenta con leche artificial. Este manejo posibilita la utilización de la leche en la fabricaci6n de quesos con un elevado valor añadido, reduce los costes de alimentaci6n y permite obtener buenos crecimientos. Sin embargo, algunos ganaderos prefieren alimentar a los cabritos con leche natural porque creen que esto incrementa la calidad de la carne

Near-infrared reflectance spectroscopy for predicting the phospholipid fraction and the total fatty acid composition of freeze-dried beef

Research on fatty acids (FA) is important because their intake is related to human health. NIRS can be a useful tool to estimate the FA of beef but due to the high moisture and the high absorbance of water makes it difficult to calibrate the analyses. This work evaluated near-infrared reflectance spectroscopy as a tool to assess the total fatty acid composition and the phospholipid fraction of fatty acids of beef using freeze-dried meat. An average of 22 unrelated pure breed young bulls from 15 European breeds were reared on a common concentrate-based diet. A total of 332 longissimus thoracis steaks were analysed for fatty acid composition and a freeze-dried sample was subjected to near-infrared spectral analysis. 220 samples (67%) were used as a calibration set with the remaining 110 (33%) being used for validation of the models obtained. There was a large variation in the total FA concentration across the animals giving a good data set for the analysis and whilst the coefficient of variation was nearly 68% for the monounsaturated FA it was only 27% for the polyunsaturated fatty acids (PUFA). PLS method was used to develop the prediction models. The models for the phospholipid fraction had a low R2 p and high standard error, while models for neutral lipid had the best performance, in general. It was not possible to obtain a good prediction of many individual PUFA concentrations being present at low concentrations and less variable than other FA. The best models were developed for Total FA, saturated FA, 9c18:1 and 16:1 with R2 p greater than 0.76. This study indicates that NIRS is a feasible and useful tool for screening purposes and it has the potential to predict most of the FA of freeze-dried beef. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Probing Tectonic Topography in the Aftermath of Continental Convergence in Central Europe

Continental topography is at the interface of processes taking place at depth in the Earth,at its surface,and above it.Topography influences society, not only in terms of slow processes of landscape change and earthquakes,but also in terms of how it affects climate.The Pannonian Basin–Carpathian Orogen System in Central and Eastern Europe represents a key natural laboratory for the development of a new generation of models for ongoing orogeny and its effect on continental topography development (Figure 1).This system comprises some of the best documented sedimentary basins in the world,located within the Alpine orogenic belt, at the transition between the western European lithosphere and the East European Craton. It includes one of the most active seismic zones in Europe,with intermediate depth (50–220 km) mantle earthquakes of significant magnitude occurring in a geographically restricted area in the Vrancea zone of southeastern Romania

Butyrophilin-like 2 regulates site-specific adaptations of intestinal γδ intraepithelial lymphocytes

Tissue-resident γδ intraepithelial lymphocytes (IELs) orchestrate innate and adaptive immune responses to maintain intestinal epithelial barrier integrity. Epithelia-specific butyrophilin-like (Btnl) molecules induce perinatal development of distinct Vγ TCR+ IELs, however, the mechanisms that control γδ IEL maintenance within discrete intestinal segments are unclear. Here, we show that Btnl2 suppressed homeostatic proliferation of γδ IELs preferentially in the ileum. High throughput transcriptomic characterization of site-specific Btnl2-KO γδ IELs reveals that Btnl2 regulated the antimicrobial response module of ileal γδ IELs. Btnl2 deficiency shapes the TCR specificities and TCRγ/δ repertoire diversity of ileal γδ IELs. During DSS-induced colitis, Btnl2-KO mice exhibit increased inflammation and delayed mucosal repair in the colon. Collectively, these data suggest that Btnl2 fine-tunes γδ IEL frequencies and TCR specificities in response to site-specific homeostatic and inflammatory cues. Hence, Btnl-mediated targeting of γδ IEL development and maintenance may help dissect their immunological functions in intestinal diseases with segment-specific manifestations