Amino Acid Composition Research Articles

Dual enzymatic preparation of flexible biocomplex with full amino-acid composition

The preparation of highly versatile flexible biomaterials able to adapt to the complex environment of the human body is an important but challenging task. In this study, a flexible biocomplex (AA-FB) was prepared by combining gelatin, polylysine, and skin using a green enzymatic cascade reaction. Interestingly, none of the raw materials used in the preparation of AA-FB introduced any compounds other than amino-acid composition, which can endow AA-FB with low biotoxicity and allergenicity, along with excellent biodegradability. Morever, AA-FB showed good physical properties: its Young's modulus was 30 times higher than that of pure gelatin hydrogel, and its water vapor transmission rate (2480.12 g/m2·24 h) was also significantly improved. AA-FB could also achieve a bacterial inhibition rate of 91.34 % against S. aureus, much higher than that of skin (28.51 %) and gelatin (41.89 %). Tests of artificial skin show that AA-FB can replace skin tissue as a protective barrier for collagen, blood vessels, and cells. As the new skin tissue is reconstructed, it gradually integrates with the normal tissue of the body until is finally metabolized.

Variability within L. albus and L. angustifolius Seeds in Dietary Fiber Components.

Lupin seeds have received increased attention due to their applications in the nutrition of humans and livestock. One of their special features is their high content of dietary fiber, which is influenced by the lupin species. No previous studies have focused on the variability in dietary fiber and its fractions within species so far. The aim of this study was to investigate the variability within L. albus and L. angustifolius (eight cultivars each) in the dietary fiber composition expressed as low-molecular-weight soluble dietary fiber (LMWSDF), soluble and insoluble non-cellulosic polysaccharides, cellulose, and Klason lignin. Additionally, we analyzed the proximate composition and the composition of amino acids and fatty acids. The results showed noticeable variability within both species not only in the total dietary fiber but also in all its fractions, especially in LMWSDF, cellulose, non-starch polysaccharides, and Klason lignin within L. angustifolius. This indicates that the cultivar choice should be based on the application for which it is used. Even though important nutrients, such as the most indispensable amino acids, are not highly variable within L. albus, dietary fiber variations can still have a marked influence on the nutritional value because of their influence on the digestibility of other nutrients.

Design, synthesis, and analysis of macrobicyclic peptides for targeting the Gαi protein.

Bicyclic peptides are important chemical tools that can function, for example, as bioactive ligands switching on/off signaling pathways mediated by guanine nucleotide-binding proteins as bicycles are more broadly applicable. Despite their relevance in medicinal chemistry, the synthesis of such peptides is challenging, and the final yield is highly dependent on the chemical composition and physicochemical properties of the scaffold. We recently discovered novel, state-specific peptide modulators targeting the Gαi protein, namely, GPM-2/GPM-3, by screening a one-bead-two-compound combinatorial library. A more detailed analysis, including sequence alignments and computer-assisted conformational studies based on the hit compounds, revealed the new peptide 10 as a potential macrobicyclic Gαi ligand sharing high sequence similarity to the known Gαi modulators. The Gαs protein was included in this study for comparison and to unravel the criteria for the specificity of modulator binding to Gαi versus Gαs. This work provides in-depth computer-assisted experimental studies for the analysis of novel macrobicyclic, library-derived Gαi protein ligands. The sequence and structural comparison of 10 with the lead compounds GPM-2 and GPM-3 reveals the importance of the size and amino acid composition of one ring of the bicyclic system and suggests features enhancing the binding affinity of the peptides to the Gαi protein.

Understanding a Core Pilin of the Type IVa Pili of Acidithiobacillus thiooxidans, PilV.

Pilins are protein subunits of pili. The pilins of type IV pili (T4P) in pathogenic bacteria are well characterized, but anything is known about the T4P proteins in acidophilic chemolithoautotrophic microorganisms such as the genus Acidithiobacillus. The interest in T4P of A. thiooxidans is because of their possible role in cell recruitment and bacterial aggregation on the surface of minerals during biooxidation of sulfide minerals. In this study we present a successful ad hoc methodology for the heterologous expression and purification of extracellular proteins such as the minor pilin PilV of the T4P of A. thiooxidans, a pilin exposed to extreme conditions of acidity and high oxidation-reduction potentials, and that interact with metal sulfides in an environment rich in dissolved minerals. Once obtained, the model structure of A. thiooxidans PilV revealed the core basic architecture of T4P pilins. Because of the acidophilic condition, we carried out in silico characterization of the protonation status of acidic and basic residues of PilV in order to calculate the ionization state at specific pH values and evaluated their pH stability. Further biophysical characterization was done using UV-visible and fluorescence spectroscopy and the results showed that PilV remains soluble and stable even after exposure to significant changes of pH. PilV has a unique amino acid composition that exhibits acid stability, with significant biotechnology implications such as biooxidation of sulfide minerals. The biophysics profiles of PilV open new paradigms about resilient proteins and stimulate the study of other pilins from extremophiles.

Development of Gluten-Free Bread Production Technology with Enhanced Nutritional Value in the Context of Kazakhstan.

This research aims to enhance the nutritional value of gluten-free bread by incorporating a diverse range of components, including additives with beneficial effects on human health, e.g., dietary fibers. The research was focused on improving the texture, taste, and nutritional content of gluten-free products by creating new recipes and including novel biological additives. The goal was to develop gluten-free bread with less than 3 ppm gluten content that can be eaten by people suffering from gluten sensitivity. The physical and chemical properties of gluten-free rice, corn, green buckwheat, chickpea, amaranth, and plantain flours were examined to understand their unique characteristics and the possibility of their mixing combination to achieve the desired results. Initially, nine recipes were prepared, and in survey research, four baking recipes were selected and tested. The composition of amino acids in the prepared gluten-free bread was determined. The variant made of corn, green buckwheat flour with plantain was found to be top-rated. Changes in the nutritional content of the new product were analyzed, and general regulations and nutritional values were identified. Experimental baking processes were carried out, leading to the successful formulation of gluten-free bread containing corn, green buckwheat, and plantain flour in a ratio of 40:40:20, meeting gluten-free requirements and demonstrating improved nutritional properties, as well as consumption properties, confirmed by surveys conducted on a group of consumers.

Nutritional composition of ultra-processed plant-based foods in the out-of-home environment: a multi-country survey with plant-based burgers.

Ultra-processed plant-based foods, such as plant-based burgers, have gained in popularity. Particularly in the out-of-home (OOH) environment, evidence regarding their nutritional profile and environmental sustainability is still evolving. Plant-based burgers available at selected OOH sites were randomly sampled in Amsterdam, Copenhagen, Lisbon and London. Plant-based burgers (patty, bread and condiment) (n 41) were lab analysed for their energy, macronutrients, amino acids and minerals content per 100 g and serving and were compared with reference values. For the plant-based burgers, the median values per 100 g were 234 kcal, 20·8 g carbohydrates, 3·5 g dietary fibre and 12·0 g fat, including 0·08 g TFS and 2·2 g SFA. Protein content was 8·9 g/100 g, with low protein quality according to amino acid composition. Median Na content was 389 mg/100 g, equivalent to 1 g salt. Compared with references, the median serving provided 31% of energy intake based on a 2000 kcal per day and contributed to carbohydrates (17-28%), dietary fibre (42%), protein (40%), total fat (48%), SFA (26%) and Na (54%). One serving provided 15-23% of the reference values for Ca, K and Mg, while higher contributions were found for Zn, Mn, P and Fe (30-67%). The ultra-processed plant-based burgers provide protein, dietary fibre and essential minerals and contain relatively high levels of energy, Na and total fats. The amino acid composition indicated low protein quality. The multifaceted nutritional profile of plant-based burgers highlights the need for manufacturers to implement improvements to better support healthy dietary habits, including reducing energy, Na and total fats.

Rationale for obtaining protein concentrate of industrial hemp seeds of Cannabis sativa L. of modern selection based on mathematical modeling and its application in food production

In recent decades interest in hemp seed concentrates, which are characterized by a valuable amino acid composition and high nutritional value, has increased. Hemp seeds are sources of vegetable protein and essential components for maintaining health due to the rich content of protein compounds, vitamins, and unsaturated fatty acids. So, production of protein concentrates from oilseeds is becoming relevant. Taking this into account, it is relevant to conduct research aimed at developing and improving the technology for obtaining protein products from the seeds of industrial hemp Cannabis Sativa L of modern selection, as well as expanding the possibility of their use as a part of a different range of food products. The seeds of industrial hemp Cannabis Sativa L of modern selection were used as objects of the research. The studies used both generally accepted and special chemical, physicochemical and physical methods for studying the quality of raw materials and finished products. The research was carried out to improve the technology for obtaining protein concentrate from the seeds of industrial hemp Cannabis Sativa L. based on mathematical modeling of the process, which showed the greatest efficiency in extracting protein concentrate using a 20% alcohol solution as an extractant. Analysis of the composition of the resulting protein concentrate showed a predominant content of globulins. At the same time, the composition of globulin fractions, in comparison with albumin, indicates a great potential for the use of globulin in the formulations of functional food products, as well as a component of targeted technological action. In general, the studies have shown the feasibility of using protein concentrates from industrial hemp seeds of Cannabis Sativa L of modern selection in food products as a functional and technological ingredient.

Metaverse Applications in Bioinformatics: A Machine Learning Framework for the Discrimination of Anti-Cancer Peptides

Bioinformatics and genomics are driving a healthcare revolution, particularly in the domain of drug discovery for anticancer peptides (ACPs). The integration of artificial intelligence (AI) has transformed healthcare, enabling personalized and immersive patient care experiences. These advanced technologies, coupled with the power of bioinformatics and genomic data, facilitate groundbreaking developments. The precise prediction of ACPs from complex biological sequences remains an ongoing challenge in the genomic area. Currently, conventional approaches such as chemotherapy, target therapy, radiotherapy, and surgery are widely used for cancer treatment. However, these methods fail to completely eradicate neoplastic cells or cancer stem cells and damage healthy tissues, resulting in morbidity and even mortality. To control such diseases, oncologists and drug designers highly desire to develop new preventive techniques with more efficiency and minor side effects. Therefore, this research provides an optimized computational-based framework for discriminating against ACPs. In addition, the proposed approach intelligently integrates four peptide encoding methods, namely amino acid occurrence analysis (AAOA), dipeptide occurrence analysis (DOA), tripeptide occurrence analysis (TOA), and enhanced pseudo amino acid composition (EPseAAC). To overcome the issue of bias and reduce true error, the synthetic minority oversampling technique (SMOTE) is applied to balance the samples against each class. The empirical results over two datasets, where the accuracy of the proposed model on the benchmark dataset is 97.56% and on the independent dataset is 95.00%, verify the effectiveness of our ensemble learning mechanism and show remarkable performance when compared with state-of-the-art (SOTA) methods. In addition, the application of metaverse technology in healthcare holds promise for transformative innovations, potentially enhancing patient experiences and providing novel solutions in the realm of preventive techniques and patient care.

Optimisation of recovery protein hydrolysate from chicken bone by steam explosion strategy and its calcium‐binding capacity and potential pro‐osteogenic activity

SummaryThis study aimed to recover protein hydrolysate from chicken bone by steam explosion and investigate its calcium‐binding capacity and potential pro‐osteogenic activity. The results showed that the recovery rate was significantly affected by pressure, time, and filling ratio. The molecular weight distribution and amino acid composition of the protein hydrolysate were also analysed. Furthermore, the protein hydrolysate extracted at 12 min, 1.8 MPa and 40% filling ratio showed well calcium‐binding capacity, and the peptides‐calcium chelate showed good stability at different temperatures. The cell experiment showed that the peptides‐calcium chelate can significantly improve the osteogenic activity of MC3T3‐E1 cells, including the proliferation, differentiation, and mineralisation. In conclusion, the steam explosion was an effective strategy to recover protein hydrolysate with well calcium‐binding capacity and potential pro‐osteogenic activity from chicken bone. This study provided new insights and theoretical bases for the application of steam explosion in extracting protein hydrolysate to improve bone health.

Physicochemical and biological properties of collagens obtained from tuna tendon by using the ultrasound-assisted extraction

This study aimed to maximize the utilization of tuna tendons, which are by-products of the tuna canning process, to obtain collagen through ultrasound-assisted extraction. Ultrasound was used to assist the extraction of vinegar-, acid-, and pepsin-soluble collagen from tuna tendons, denoted as VUTC, AUTC, and PUTC, respectively. The yield ranged from 10% to 15%, and the collagen solubility was 0.5–0.7 mg protein/mg collagen. The color differed among the collagen samples. Tuna tendon collagens comprised γ-, β-, α1-, and α2-chains, in accordance with type I calf skin collagen. Regarding the amino acid composition, there were high amounts of glycine, proline, glutamic acid, alanine, hydroxyproline, and aspartic acid. Salt concentration and pH effects on the solubility of collagen were evaluated. The samples were less soluble at higher salt concentrations and had good solubility at low pH. Fourier transform infrared spectroscopy showed the presence of a triple helix. Fractional viscosity and differential scanning calorimetry (DSC) analysis indicated a degradation temperature of 30–36 °C and 167–171 °C, respectively. Finally, tuna tendon collagen had antioxidant and immune-enhancing activities and did not exert cytotoxicity.

Amino Acid Composition in Different Tissues of Iceland Scallop from the Barents Sea.

The Iceland scallop from the Barents Sea is a commercially important species with promising aquaculture potential, but information on the biochemical properties of its tissues is limited. Our analysis of the adductor muscle, gonad, and mantle of this bivalve mollusk from coastal waters provided insight into its amino acid composition. Biochemical analysis revealed predominant levels of glycine (11.8, 11.5, and 9.6 mg g-1, respectively) and arginine (11.2, 8.3, and 5.8 mg g-1, respectively). While multivariate comparisons did not reveal significant differences in amino acid composition between the tissues, single comparisons showed significantly higher levels of arginine and leucine in the adductor muscle compared to those of the mantle. The abundant presence of glycine and arginine underscores their importance in maintaining basic physiological processes, consistent with other scallop species. Redundancy analysis identified water depth and scallop gonad index as influential factors shaping the amino acid profile in the adductor muscle. In the case of the mantle, water temperature emerged as the main driver of amino acid content. Our results confirm the richness of essential amino acids in scallop by-products and highlight their potential for human consumption, production of feed ingredients for farmed animals, and nutraceuticals.

Genomic prediction reveals unexplored variation in grain protein and lysine content across a vast winter wheat genebank collection.

Globally, wheat (Triticum aestivum L.) is a major source of proteins in human nutrition despite its unbalanced amino acid composition. The low lysine content in the protein fraction of wheat can lead to protein-energy-malnutrition prominently in developing countries. A promising strategy to overcome this problem is to breed varieties which combine high protein content with high lysine content. Nevertheless, this requires the incorporation of yet undefined donor genotypes into pre-breeding programs. Genebank collections are suspected to harbor the needed genetic diversity. In the 1970s, a large-scale screening of protein traits was conducted for the wheat genebank collection in Gatersleben; however, this data has been poorly mined so far. In the present study, a large historical dataset on protein content and lysine content of 4,971 accessions was curated, strictly corrected for outliers as well as for unreplicated data and consolidated as the corresponding adjusted entry means. Four genomic prediction approaches were compared based on the ability to accurately predict the traits of interest. High-quality phenotypic data of 558 accessions was leveraged by engaging the best performing prediction model, namely EG-BLUP. Finally, this publication incorporates predicted phenotypes of 7,651 accessions of the winter wheat collection. Five accessions were proposed as donor genotypes due to the combination of outstanding high protein content as well as lysine content. Further investigation of the passport data suggested an association of the adjusted lysine content with the elevation of the collecting site. This publicly available information can facilitate future pre-breeding activities.

Germinal centers are permissive to subdominant antibody responses.

A protective humoral response to pathogens requires the development of high affinity antibodies in germinal centers (GC). The combination of antigens available during immunization has a strong impact on the strength and breadth of the antibody response. Antigens can display various levels of immunogenicity, and a hierarchy of immunodominance arises when the GC response to an antigen dampens the response to other antigens. Immunodominance is a challenge for the development of vaccines to mutating viruses, and for the development of broadly neutralizing antibodies. The extent by which antigens with different levels of immunogenicity compete for the induction of high affinity antibodies and therefore contribute to immunodominance is not known. Here, we perform in silico simulations of the GC response, using a structural representation of antigens with complex surface amino acid composition and topology. We generate antigens with complex domains of different levels of immunogenicity and perform simulations with combinations of these domains. We found that GC dynamics were driven by the most immunogenic domain and immunodominance arose as affinity maturation to less immunogenic domain was inhibited. However, this inhibition was moderate since the less immunogenic domain exhibited a weak GC response in the absence of the most immunogenic domain. Less immunogenic domains reduced the dominance of GC responses to more immunogenic domains, albeit at a later time point. The simulations suggest that increased vaccine valency may decrease immunodominance of the GC response to strongly immunogenic domains and therefore, act as a potential strategy for the natural induction of broadly neutralizing antibodies in GC reactions.

From amino acid analysis to improved gel properties: The role of dl-valine in Landaise goose myofibrillar protein

The impact of exogenous limiting amino acids on protein gel formation was investigated to enhance the gelation properties of Landaise goose myofibrillar protein (MP). Amino acid composition and gel properties were analyzed, and homologous protein modeling and molecular docking techniques were used to simulate binding sites. Valine was identified as the first limiting amino acid. The addition of 0.075 % dl-valine proved optimal to enhance the gel strength (59.5 g) and water retention (76.76 %) of MP gels. Hydrophobic interactions and disulfide bonds were found to be the main forces maintaining conformational stability of the MP-dl-valine gels. The propyl group of dl-valine can form hydrophobic interactions with protein, contributing to stable complexes. DL valine could also strengthen chemical bonds and secondary structure, convert free water to immobile water, and improve the microstructure of the gel. Therefore, valine can be utilized as a nutritional and gel enhancer in Landaise goose meat products.

Whole-Genome Sequencing and Search for Determinants of Resistance to Benzalkonium Chloride in <I>Burkholderia pseudomallei</I>

The aim of the study was to carry out whole-genome sequencing and comparative analysis of the original and benzalkonium chloride-resistant strains of Burkholderia pseudomallei.Materials and methods. We used the strain B. pseudomallei 134 and resistant to benzalkonium chloride B. pseudomallei 134K. Whole-genome sequencing was conducted on the MiSeq Reagent Kit v3 platform (600-cucle).Genome assembly for both strains was performed with the help of SPAdes v3.11.1. In order to compare genome sequences of the studied strains, Snippy v4.6.0 software was applied. MEGA X program was used to align the nucleotide and amino acid sequences.Results and discussion. The search and analysis of determinants responsible for the emergence of resistance to biocides in B. pseudomallei 134K have revealed two genes: the TetR transcriptional repressor gene and the AmrAB-OprA efflux pump gene. A single nucleotide polymorphism has been found in the TetR regulator, which led to the replacement of serine by proline in the mutant protein, and, as a result, a change in its secondary structure. It is believed that this mutation causes the loss of regulatory protein functionality, resulting in an increased expression of the efflux pump genes (AcrB/AcrD/AcrF) regulated by it. This follows by both, decrease in the level of sensitivity to benzalkonium chloride and the emergence of resistance to ceftazidime. In the AmrAB-OprA efflux pump gene, an insertion of 16 nucleotides has been detected at the position 544 of the amrA operon, which led to an increase in the length of the cistron, a shift in the reading frame, a change in the amino acid composition, and, as a result, a change in the secondary structure of the encoded protein. It is most likely that this mutation contributes to the loss of AmrAB-OprA operon function and the failure of normal outflow of xenobiotics from the cytoplasm of the microorganism. This assumption is evidenced by the loss of resistance to gentamicin in the mutant strain.

Unstable environmental conditions constrain the fine-tune between opsin sensitivity and underwater light in an Amazon forest stream fish.

Visual adaptations can stem from variations in amino acid composition, chromophore utilization, and differential opsin gene expression levels, enabling individuals to adjust their light sensitivity to environmental lighting conditions. In stable environments, adaptations often involve amino acid substitutions, whereas in unstable conditions, differential gene expression may be a more relevant mechanism. Amazon forest streams present diverse underwater lighting conditions and experience short-term water colour fluctuations. In these environments, it is less likely for genetic and amino acid sequences to undergo modifications that tailor opsin proteins to the prevailing lighting conditions, particularly in species having several copies of the same gene. The sailfin tetra, Crenuchus spilurus, inhabits black and clear water Amazon forest streams. The long-wavelength sensitivity (LWS) is an important component for foraging and courtship. Here, we investigated LWS opsin genes in the sailfin tetra. Three copies of LWS1 and two copies of LWS2 genes were found. The maximum absorbance wavelength (λmax) estimated from the amino acid sequences of LWS1 genes exhibited variation among the different copies. In contrast, the copies of LWS2 genes showed identical expected λmax values. Although the amino acid positions affecting λmax varied among LWS genes, they remained consistent among populations living in different water colours. The relative expression levels of LWS genes differed between gene copies. While not formally tested, our results suggest that in fluctuating environments, visual adaptations may primarily stem from alterations in gene expression profiles and/or chromophore usage rather than precise genetic tuning of protein light sensitivity to environmental lighting conditions.

Genomic basis of environmental adaptation in the widespread poly-extremophilic Exiguobacterium group.

Delineating cohesive ecological units and determining the genetic basis for their environmental adaptation are among the most important objectives in microbiology. In the last decade, many studies have been devoted to characterizing the genetic diversity in microbial populations to address these issues. However, the impact of extreme environmental conditions, such as temperature and salinity, on microbial ecology and evolution remains unclear so far. In order to better understand the mechanisms of adaptation, we studied the (pan)genome of Exiguobacterium, a poly-extremophile bacterium able to grow in a wide range of environments, from permafrost to hot springs. To have the genome for all known Exiguobacterium type strains, we first sequenced those that were not yet available. Using a reverse-ecology approach, we showed how the integration of phylogenomic information, genomic features, gene and pathway enrichment data, regulatory element analyses, protein amino acid composition, and protein structure analyses of the entire Exiguobacterium pangenome allows to sharply delineate ecological units consisting of mesophilic, psychrophilic, halophilic-mesophilic, and halophilic-thermophilic ecotypes. This in-depth study clarified the genetic basis of the defined ecotypes and identified some key mechanisms driving the environmental adaptation to extreme environments. Our study points the way to organizing the vast microbial diversity into meaningful ecologically units, which, in turn, provides insight into how microbial communities adapt and respond to different environmental conditions in a changing world.

Effects of Fishmeal Substitution with Mealworm Meals (Tenebrio molitor and Alphitobius diaperinus) on the Growth, Physiobiochemical Response, Digesta Microbiome, and Immune Genes Expression of Atlantic Salmon (Salmo salar).

A 12-week growth trial was conducted to assess the effects of mealworm meals, as a substitution for fishmeal, on the growth, physiobiochemical responses, digesta microbiome, and immune-related genes expression of Atlantic salmon (Salmo salar). Twenty Atlantic salmon parr (38.5 ± 0.1 g, initial weight) were stocked into each of 16 tanks in a recirculating aquaculture system. A fishmeal-based diet (100% FM) was used as the control treatment and was compared with three test diets where: (1) fishmeal was partially (50%) replaced with defatted mealworm meal, Tenebrio molitor (50% DMM), (2) fishmeal was fully replaced with defatted mealworm meal (100% DMM), and (3) fishmeal was partially replaced with whole lesser mealworm meal, Alphitobius diaperinus (50% WMM). All substitutions were done on a crude protein basis. Each of the four experimental diets was evaluated in quadruplicate tanks as part of randomized design. The results indicated that Atlantic salmon showed high survival (greater or equal to 98.8%), and no significant difference in final growth, feed efficiency, feces stability and condition indices. Hepatosomatic index was lower in fish fed 100% DMM and 50% WMM when compared to fish fed the control diet (100% FM). Whole-body proximate and amino acid compositions were not statistically different between treatments, while essential fatty acids, including linolenic, eicosapentaenoic acid, and homo-a-linolenic, were lower in fish fed 100% DMM. Plasma parameters (total protein, alanine aminotransferase, alkaline phosphatase, and total iron-binding capacity), hepatic peroxide, and antioxidant enzymes were not significantly affected by dietary substitutions, whereas plasma immunoglobulin M showed significantly higher levels in fish fed 50% DMM and 100% DMM when compared to fish fed the control diet (100% FM). The inclusion of mealworm meals significantly impacted the overall microbiome composition but not the richness and evenness of the salmon digesta microbiomes compared to control. The most common genus in all treatments was Pseudomonas, which has been previously shown to have both commensal and pathogenic members. The relative expressions of growth (IGF-I) and protein synthesis (TIPRL) were not significantly different between the treatments, whereas immunoglobulin genes (IgM, IgD, and IgT) were significantly upregulated in fish fed the DMM diets when compared to fish fed the control diet. Overall, this study suggests that the mealworm meals tested could be suitable alternatives to fishmeal in the diet of Atlantic salmon.

Problems and Collisions of Vaccinology

The article discusses the limitations of the protective potential of the immune system associated with the peculiarities of the evolutionary mechanisms of the emergence of protein diversity and the late emergence in the evolution of the adaptive immune system, as well as problems associated with the formation of immunity to viral infections and immune collisions during vaccination. Using the example of hemagglutinin of the H1N1 influenza virus and S protein of the SARS-Cov-2 coronavirus, the features of the amino acid composition of their immunodominant (NA1 and S1) and subdominant (NA2 and S2) subunits are illustrated and the possibility of creating a universal vaccine against influenza viruses is analyzed. The principle of a new method for detecting linear peptide immunoepitopes recognized by MHC I and II and biomarkers of long-term immunity in surface viral proteins used as vaccines is described. The model of proteolysis of vaccine proteins in immunoprotesomes and lysosomes, features of the amino acid composition of surface proteins of viruses to which vaccines cause long-term immunity, and viruses to which vaccines have not yet been developed, as well as possible collisions with mRNA vaccines are examined. Possible collisions with mRNA vaccines are also being considered in connection with the identification of gene encoding limitations.

Serum metabolic signatures for Alzheimer’s Disease reveal alterations in amino acid composition: a validation study

IntroductionAlzheimer’s Disease (AD) is complex and novel approaches are urgently needed to aid in diagnosis. Blood is frequently used as a source for biomarkers; however, its complexity prevents proper detection. The analytical power of metabolomics, coupled with statistical tools, can assist in reducing this complexity.ObjectivesThus, we sought to validate a previously proposed panel of metabolic blood-based biomarkers for AD and expand our understanding of the pathological mechanisms involved in AD that are reflected in the blood.MethodsIn the validation cohort serum and plasma were collected from 25 AD patients and 25 healthy controls. Serum was analysed for metabolites using nuclear magnetic resonance (NMR) spectroscopy, while plasma was tested for markers of neuronal damage and AD hallmark proteins using single molecule array (SIMOA).ResultsThe diagnostic performance of the metabolite biomarker panel was confirmed using sparse-partial least squares discriminant analysis (sPLS-DA) with an area under the curve (AUC) of 0.73 (95% confidence interval: 0.59–0.87). Pyruvic acid and valine were consistently reduced in the discovery and validation cohorts. Pathway analysis of significantly altered metabolites in the validation set revealed that they are involved in branched-chain amino acids (BCAAs) and energy metabolism (glycolysis and gluconeogenesis). Additionally, strong positive correlations were observed for valine and isoleucine between cerebrospinal fluid p-tau and t-tau.ConclusionsOur proposed panel of metabolites was successfully validated using a combined approach of NMR and sPLS-DA. It was discovered that cognitive-impairment-related metabolites belong to BCAAs and are involved in energy metabolism.