Computational Saturation Mutagenesis of SARS-CoV-1 Spike Glycoprotein: Stability, Binding Affinity, and Comparison With SARS-CoV-2

Severe Acute respiratory syndrome coronavirus (SARS-CoV-1) attaches to the host cell surface to initiate the interaction between the receptor-binding domain (RBD) of its spike glycoprotein (S) and the human Angiotensin-converting enzyme (hACE2) receptor. SARS-CoV-1 mutates frequently because of its RNA genome, which challenges the antiviral development. Here, we per-formed computational saturation mutagenesis of the S protein of SARS-CoV-1 to identify the residues crucial for its functions. We used the structure-based energy calculations to analyze the effects of the missense mutations on the SARS-CoV-1 S stability and the binding affinity with hACE2. The sequence and structure alignment showed similarities between the S proteins of SARS-CoV-1 and SARS-CoV-2. Interestingly, we found that target mutations of S protein amino acids generate similar effects on their stabilities between SARS-CoV-1 and SARS-CoV-2. For example, G839W of SARS-CoV-1 corresponds to G857W of SARS-CoV-2, which decrease the stability of their S glycoproteins. The viral mutation analysis of the two different SARS-CoV-1 isolates showed that mutations, T487S and L472P, weakened the S-hACE2 binding of the 2003–2004 SARS-CoV-1 isolate. In addition, the mutations of L472P and F360S destabilized the 2003–2004 viral isolate. We further predicted that many mutations on N-linked glycosylation sites would increase the stability of the S glycoprotein. Our results can be of therapeutic importance in the design of antivirals or vaccines against SARS-CoV-1 and SARS-CoV-2.

Efeitos da suplementação nutricional na massa muscular, força muscular e desempenho físico em idosos sarcopênicos

OBJETIVO: analisar os efeitos da suplementação nutricional na Massa Muscular, Força Muscular e no Desempenho Físico deidosos sarcopênicos. MÉTODO: Revisão integrativa realizada através das bases de dados: PubMed e Cochrane Library, utilizandoos descritores do Medical Subject Headings (MeSH): “sarcopenia”, “food supplements”, “protein”, “amino acids”, “leucine”, “wheyprotein”, “vitamin D” e ‘HMB”. RESULTADOS: Para a pesquisa dos artigos foram selecionados os que possuíam critérios de clarezaem relação ao título, identificando 22 artigos, sendo excluídos 12, restando apenas 10 que estavam condizentes com o objetivoprincipal. CONCLUSÃO: A ingestão adequada de nutrientes é a melhor forma de tratar a sarcopenia. A intervenção nutricional, comingestão de alta quantidade de proteínas de soro do leite promove a síntese de proteínas no corpo, preservando ou aumentandoos parâmetros observados. A suplementação nutricional é eficaz no tratamento da sarcopenia em idosos e os seus efeitos sãopositivos nas medidas de sarcopenia.

Intensification of lamb salting process with low frequency ultrasound

Young lamb has high nutritional properties due to its high protein, amino acids, vitamins and microelements content. However, the specific odor and the high fat pour point are the main obstacles to the industrial use of lamb. The purpose of our research was to study the physical and chemical characteristics of raw lamb after ultrasonic salting and to select the optimal processing conditions and their economic justification. Experimental samples were salted in the devices UOM - 2 and PSB - Gals at 35 kHz ultrasound frequency, as well as using an ultrasonic submersible emitter at 26 kHz. Ultrasonic treatment has led to an increase in the pH and moisture content of the raw material, as well as in product yield. With an increase in the salting time, the water activity (Aw) decreased. Based on the results of physicochemical samples studies and comparative analysis of the economic efficiency, a submersible ultrasonic emitter with an ultrasonic frequency of 26 kHz and a salting duration of 12 hours was recommended for lamb delicacies salting.

316 Determination of the Chemical and Phytochemical Composition of the Methanolic Extract of Urochloa Humidicola for Use as a Phytogenic Additive in Ruminant Diets

Plant extract is an excellent alternative to reduce methane emissions and ameliorate ruminal fermentation due the presence of the secondary metabolites, however, there are many studies with plants used on human’s diet that shows a good result but may occur competition and elevate the costs for the system. Plants consumed by animal have secondary metabolites in quantity and diversity, it can be a good strategy. This work aimed to determine the bromatological composition and characterize the Urochloa humidicola methanol extract such as the presence of secondary metabolites. The samples of the leaves of U. humidicola were collected, dried in the shade with temperature below 40°C, ground in a willey mill in 2 mm particles and subjected to cold maceration with methanol. The solution obtained was filtered by filter paper and concentrated in a rotary evaporator and put to finish the process, drying under airflow. The results of bromatological analyses were subjected to ANOVA by comparing averages by Fisher’s test using the 9.1 Saeg software and phytochemical prospecting testes were characterized as the intensity of the presence of each class of metabolites and represented via the cross-system where:(+++) implies a large presence, (++) implies a considerable presence, (+) implies a small presence and (0) implies a no presence. The dry crude methanolic extract was subjected to analysis of chemical composition and phytochemical prospecting. The extract showed 10.20% crude protein and 35% ether extract and traces of fibrous constituents, because the methanol extraction extracted only soluble constituents. A phytochemical prospecting was positive for the presence of saponin. tannin, alkaloids, catechins, non-protein amino acids and saccharides and was negative for the presence of flavonoids and purines. The U. humidicola methanol extract can be used as a phytogenic additive in the feeding of ruminants.

Comparison of Nutritional and Nutraceutical Properties of Burdock Roots Cultivated in Fengxian and Peixian of China

This study aimed to analyze and compare the nutritional quality of powders of burdock root from Fengxian (FX) and Peixian (PX) in China. The nutrient composition including carbohydrates, protein, amino acids, vitamin C, carotenoids, as well as total phenols, total flavonoids and phenolic compounds were investigated in addition to in vitro antioxidant capacity. The results showed that the basic nutrients of burdock root powder (BRP) in both locations did not have significant differences (p > 0.05), although the in vitro antioxidant capacity of BRP of Fengxian (F-BRP) was greater than that of PX (p < 0.05). The burdock root peel powder (BRPP) possessed more phenolics and stronger in vitro antioxidant capacity than the burdock root powder (BRP) and peeled burdock root powder (PBRP) (p < 0.05). Moreover, better quality burdock root was obtained from FX. F-BRP was consequently analyzed by ultra-performance liquid chromatography tandem mass spectrometry for its phenolic composition. Seventeen phenolics, mainly caffeoylquinic acids, were detected. In addition, a total of 181 volatile compounds belonging to eight types were detected including alcohols, aldehydes, ketones, alkenes, esters, acids, linear or aromatic hydrocarbons, and others. The diverse compounds found in this study can provide a theoretical basis for the development and utilization of burdock in the food industry.

Identification and Characterization of an Affimer Affinity Reagent for the Detection of the cAMP Sensor, EPAC1

An exchange protein directly activated by cAMP 1 (EPAC1) is an intracellular sensor for cAMP that is involved in a wide variety of cellular and physiological processes in health and disease. However, reagents are lacking to study its association with intracellular cAMP nanodomains. Here, we use non-antibody Affimer protein scaffolds to develop isoform-selective protein binders of EPAC1. Phage-display screens were carried out against purified, biotinylated human recombinant EPAC1ΔDEP protein (amino acids 149–811), which identified five potential EPAC1-selective Affimer binders. Dot blots and indirect ELISA assays were next used to identify Affimer 780A as the top EPAC1 binder. Mutagenesis studies further revealed a potential interaction site for 780A within the EPAC1 cyclic nucleotide binding domain (CNBD). In addition, 780A was shown to co-precipitate EPAC1 from transfected cells and co-localize with both wild-type EPAC1 and a mis-targeting mutant of EPAC1(K212R), predominantly in perinuclear and cytosolic regions of cells, respectively. As a novel EPAC1-selective binder, 780A therefore has the potential to be used in future studies to further understand compartmentalization of the cAMP-EPAC1 signaling system.

Structure-based screening of drug candidates targeting the SARS-CoV-2 envelope protein

The COVID-19 (coronavirus disease 2019) pandemic is caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2). SARS-CoV-2 produces a small hydrophobic envelope (E) protein which shares high homology with SARS-CoV E protein. By patch-clamp recording, the E protein is demonstrated to be a cation-selective ion channel. Furthermore, the SARS-CoV-2 E protein can be blocked by a SARS-CoV E protein inhibitor hexamethylene amiloride. Using structural model and virtual screening, another E protein inhibitor AZD5153 is discovered. AZD5153 is a bromodomain protein 4 inhibitor against hematologic malignancies in clinical trial. The E protein amino acids Phe23 and Val29 are key determinants for AZD5153 sensitivity. This study provides two promising lead compounds and a functional assay of SARS-CoV-2 E protein for the future drug candidate discovery.

Changes in the Nutrient Composition of Barley Grain (Hordeum vulgare L.) and of Morphological Fractions of Sprouts

The objectives of the current study were (1) to evaluate the effect of sprouting on protein, amino acids, fats, fatty acids, starch, total soluble carbohydrates, and ß-D-glucan content of barley grains and (2) to know the content of these nutrients in the morphological fractions of sprouts: green shoot, residual structure of sprouted grain (RSSG), residual structure of sprouted grain plus unsprouted grain (RSSG plus UG), and root fractions and to determine the proportion of each of these fractions (on fresh and dry basis) in the sprout biomass. Barley grain was sprouted in a commercial germination chamber for a period of 6 days. Raw grain was used as a control. Results showed that crude protein, ether extract, total soluble carbohydrates, and cellulose content increased, whereas starch and ß-D-glucan content decreased in sprouted when compared with the control grain. Amino acid and fatty acid profiles were also affected. Thus, aspartic acid, threonine, alanine, valine, isoleucine, lysine, and tryptophan content increased and only that of glutamic acid decreased after sprouting. Regarding fatty acids, an increase in the relative concentration of C18 : 0 and C18:3n-3 and a decrease in that of C18:1n-9 were detected. Partitioning of sprouted barley into three morphological component fractions showed that the residual structures of sprouted grains plus unsprouted grain fraction made up 82.9% and 93.6% of sprout biomass, on fresh and DM basis, respectively, and the remainder was provided by the root fraction, 10.3% and 3.2%, respectively, and by the green shoot fraction, 6.8% and 3.1%, respectively. The three morphological fractions differed in the content of the most analyzed nutrients.

The key amino acids of E protein involved in early flavivirus infection: viral entry

Flaviviruses are enveloped viruses that infect multiple hosts. Envelope proteins are the outermost proteins in the structure of flaviviruses and mediate viral infection. Studies indicate that flaviviruses mainly use envelope proteins to bind to cell attachment receptors and endocytic receptors for the entry step. Here, we present current findings regarding key envelope protein amino acids that participate in the flavivirus early infection process. Among these sites, most are located in special positions of the protein structure, such as the α-helix in the stem region and the hinge region between domains I and II, motifs that potentially affect the interaction between different domains. Some of these sites are located in positions involved in conformational changes in envelope proteins. In summary, we summarize and discuss the key envelope protein residues that affect the entry process of flaviviruses, including the process of their discovery and the mechanisms that affect early infection.