Lysine Content Research Articles

Nitrogen Level Impacts the Dynamic Changes in Nitrogen Metabolism, and Carbohydrate and Anthocyanin Biosynthesis Improves the Kernel Nutritional Quality of Purple Waxy Maize

Waxy corn is a special type of maize primarily consumed as a fresh vegetable by humans. Nitrogen (N) plays an essential role in regulating the growth progression, maturation, yield, and quality of waxy maize. A reasonable N application rate is vital for boosting the accumulation of both N and carbon (C) in the grains, thereby synergistically enhancing the grain quality. However, the impact of varying N levels on the dynamic changes in N metabolism, carbohydrate formation, and anthocyanin synthesis in purple waxy corn kernels, as well as the regulatory relationships among these processes, remains unclear. To explore the effects of varying N application rates on the N metabolism, carbohydrate formation, and anthocyanin synthesis in kernels during grain filling, a two-year field experiment was carried out using the purple waxy maize variety Jinnuo20 (JN20). This study examined the different N levels, specifically 0 (N0), 120 (N1), 240 (N2), and 360 (N3) kg N ha−1. The results of the analysis revealed that, for nearly all traits measured, the N application rate of N2 was the most suitable. Compared to the N0 treatment, the accumulation and content of anthocyanins, total nitrogen, soluble sugars, amylopectin, and C/N ratio in grains increased by an average of 35.62%, 11.49%, 12.84%, 23.74%, 13.00%, and 1.87% under N2 treatment over five filling stages within two years, respectively, while the harmful compound nitrite content only increased by an average of 30.2%. Correspondingly, the activities of related enzymes also significantly increased and were maintained under N2 treatment compared to N0 treatment. Regression and correlation analysis results revealed that the amount of anthocyanin accumulation was highly positively correlated with the activities of phenylalanine ammonia-lyase (PAL) and flavanone 3-hydroxylase (F3H), but negatively correlated with anthocyanidin synthase (ANS) and UDP-glycose: flavonoid-3-O-glycosyltransferase (UFGT) activity, nitrate reductase (NR), and glutamine synthetase (GS) showed significant positive correlations with the total nitrogen content and lysine content, and a significant negative correlation with nitrite, while soluble sugars were negatively with ADP-glucose pyrophosphorylase (AGPase) activity, and amylopectin content was positively correlated with the activities of soluble starch synthase (SSS), starch branching enzyme (SBE), and starch debranching enzyme (SDBE), respectively. Furthermore, there were positive or negative correlations among the detected traits. Hence, a reasonable N application rate improves purple waxy corn kernel nutritional quality by regulating N metabolism, as well as carbohydrate and anthocyanin biosynthesis.

Grain Lysine enrichment and improved stress tolerance in rice through protein engineering.

Amino acids are a major source of nourishment for people living in regions where rice is a staple food. However, rice grain is deficient in essential amino acids, such as lysine. The activity of dihydrodipicolinate synthase (DHDPS) enzyme is crucial for lysine production in higher plants, but it is highly regulated through a feedback inhibition by its end product lysine, leading to its limited activity in the grain and resulting in low lysine accumulation. We identified lysine binding sites in the DHDPS enzyme and introduced key mutations to make it lysine feedback insensitive. Using in vivo analysis and functional complementation assays, we confirmed that protein engineering of the DHDPS renders it insensitive to lysine. Expression of mutated DHDPS resulted in 29 % higher lysine and 15 % higher protein accumulation in rice grains than the wild type. Importantly, the lysine content in transgenic grains was maintained in cooked rice. Further, the transgenic plants exhibited enhanced stress tolerance along with better antioxidant levels, improved photosynthesis, and higher grain yield compared to wild type plants. We have shown for the first time in rice that protein engineering of DHDPS can lead to accumulation of lysine in grains and impart abiotic stress tolerance. This approach could improve health in regions with nutrient deficiencies and environmental stressors that challenge food production and human health.

Protein and lysine improvement harnessed by a signal chain of red light-emitting diode light in Chlorella pyrenoidosa

Microalgae are emerging as a novel single-cell protein source that can substitute traditional plant protein feeds. In this investigation, lysine and protein accumulation in Chlorella pyrenoidosa were significantly enhanced under red light-emitting diode light, addressing challenge of limiting amino acid in plant proteins. The study employed targeted metabolomics, HPLC, and qRT-PCR to validate the light-induced pathway triggering lysine biosynthesis. Specifically, the pathway involves Ca2+-CaM as an intermediary in signal transduction, which directly inhibits PEPC activity. This inhibition directs a significant carbon flux towards central carbon metabolism, resulting in increased pyruvate levels—a critical precursor for lysine biosynthesis via the diaminopimelate pathway. Ultimately, the content of protein and lysine under red light increased by 36.02 % and 99.56 %, respectively, compared to those under white light. These findings provide a novel orientation for the precise regulation of lysine accumulation in microalgae, and moreover lay a solid theoretical foundation for producing microalgal proteins.

Amaranth: Multipurpose Agroindustrial Crop

Amaranthus cruentus L. (varieties: Juana, Aurelia, Elena) and Amaranthus viridis L. (variety: Callaloo) have long been utilized in food products for human consumption in Central and South America. However, there is limited information on the chemical composition of these species’ leaves and grains grown in Puerto Rico. This study aimed to fill this gap by evaluating the nutritional profile of these four amaranth varieties cultivated in Puerto Rico. A compositional analysis was conducted using official methods, focusing on lysine, protein, dietary fiber, and mineral content. The results showed high lysine content in both species. Significant differences (p < 0.05) were found in crude protein levels among the leaves, with Elena (23%) and Aurelia (21%) showing the highest values. While protein content among grains averaged 19%, there were no significant differences between varieties. The analysis of dietary fiber revealed significant differences (p < 0.05) in insoluble dietary fiber (IDF) and total dietary fiber (TDF) for the leaves and in IDF, soluble dietary fiber (SDF), and TDF for the grains. Additionally, calcium, magnesium, and phosphorus concentrations differed significantly (p < 0.05) in the leaves, while iron, potassium, and zinc showed no significant variation. Significant differences were found in the grains for calcium, magnesium, iron, and phosphorus. This research highlights the excellent nutritional value of amaranth leaves and grains grown in Puerto Rico, with Elena and Aurelia having exceptionally high protein content in their leaves.

Allelic Diversity and Development of Breeder-Friendly Marker Specific to floury2 Gene Regulating the Accumulation of α-Zeins and Essential Amino Acids in Maize Kernel.

Maize zeins lack essential amino acids, such as methionine, lysine, and tryptophan. The floury2 (fl2) mutation reduces zein synthesis and increases methionine and lysine content in kernels. In this study, fl2 gene (1612bp) was sequenced in eight wild-type and two mutant inbreds and detected 218 SNPs and 18 InDels. Transversion of C to T at 343bp position caused the substitution of alanine by valine in the fl2 mutant. A PCR-based marker (FL-SNP-CT) was developed, which distinguished the favorable mutant fl2 allele (T) from the wild-type (C) Fl2 allele. Gene-based diversity analysis using seven gene-based InDel markers grouped 48 inbred lines into three major clusters, with an average genetic dissimilarity coefficient of 0.534. The average major allele frequency, gene diversity, heterozygosity, and polymorphism information content of the InDel markers were 0.701, 0.392, 0.039, and 0.318, respectively. Haplotype analysis revealed 29 haplotypes of fl2 gene among these 48 inbreds. Amino acid substitution (Ala-Val) at the signal peptide cleavage site produced unprocessed 24-kDa mutant protein instead of 22-kDa zein found in normal genotype. Eight paralogues of fl2 detected in the study showed variation in exon lengths (616-1170bp) and translation lengths (135-267 amino acids). Orthologue analysis among 15 accessions of Sorghum bicolor and two accessions of Saccharum spontaneum revealed a single exon in fl2 gene, ranging from 267 to 810bp. The study elucidated the molecular basis of fl2 mutation and reported a breeder-friendly marker for molecular breeding programs. This is the first study to characterize fl2 gene in a set of subtropically adapted inbreds.

Some Nutritional Value Aspects of Barley and Oat and Their Impact in Human Nutrition and Healthy Life.

Nowadays, there is a general concern regarding the increasing global talk about functional foods that respond to our demands and needs as consumers in order to maintain health and body weight through a correctly balanced diet. Cereals are key elements of nutrition and a healthy diet, and they also play a significant role in health promotion due to the useful nutrient content. Therefore, this work aims to identify barley and oat genotypes suitable for human nutrition and to achieve practical results for their widespread use in preventing or treating certain chronic diseases by analyzing the nutritional and physical properties of 52 genotypes of oat and barley conserved in Suceava Gene Bank, Romania. The first part of this manuscript is the presentation of these accessions and the evaluation of their most important properties. For oat and barley cultivars, detailed processing was carried out, involving the computation of variation amplitude, coefficients of correlation and cluster analyses, both for biochemical (protein, lysine and tryptophan contents) and physical (test weight and seed weight) properties. The results indicated high variability between oat and barley varieties. Thus, according to the results, the 26 varieties of oat exhibited almost double the content of lysine compared to barley seeds, while tryptophan had higher values in barley than in oat seeds. Overall, both species play an essential role in human nutrition, barley being important because of its high protein content and higher productivity compared to oats, which, although not as productive, have better quality seeds due to their higher lysine content. The results presented are not only of scientific interest but also have practical implications for agriculture, food safety, nutrition and human health. The documented information will facilitate new studies needed to contribute to improving human nutrition and health.

Co-fermentation with multiple-strains and cellulase enhances the nutritional quality of hot-pressed rapeseed meal by modifying its physicochemical properties

The thermal damage of proteins and the presence of anti-nutritional factors seriously affect the quality of hot-pressed rapeseed meal (RSM), thereby limiting its utilization in the feed and food industry. Previously, we developed a co-fermentation method with multi-strains and cellulase that can simultaneously degrade the protein and anti-nutrient components in hot-pressed RSM. This study aimed to evaluate the impact of fermentation on the physicochemical properties and nutritional value of hot-pressed RSM. After fermentation, the levels of neutral detergent fiber (NDF) and glucosinolate (GLS) in hot pressed RSM decreased by 41.47% and 77.30%, respectively, and the trichloroacetic acid-soluble protein (TASP) and lysine contents increased by 1007.62% and 65.25%, respectively. During the fermentation process, the extensive hydrolysis of rapeseed protein resulted in a 49.11% yield of peptides < 3K Da, and intensified the umami, saltiness, sweetness, and bitterness of fermented rapeseed meal (FRSM). Animal experiments demonstrated that co-fermentation effectively enhances the ileal digestibility of most amino acids in hot-pressed RSM, as well as the deposition of nitrogen and energy, thereby improving the growth of growing pigs. Overall, the co-fermentation with microbes and cellulase is an effective strategy for enhancing the quality of hot-pressed RSM.

Insulin Regulation of Lysine and α-Aminoadipic Acid Dynamics and Amino Metabolites in Women With and Without Insulin Resistance.

Insulin is a key regulator of amino acids (AAs) metabolism. Many plasma AAs, including lysine and its metabolite, α-aminoadipic acid (α-AA), a predictor for developing diabetes, are elevated in insulin resistance. In 18 insulin-resistant (IR) over-weight women with polycystic ovary syndrome compared to 12 lean controls, high physiological insulin during a euglycemic clamp failed to normalize many elevated AA metabolites, including branched-chain and aromatic AA, alphaamino- butyric acid, and lysine, but normalized α-AA. To understand the underpinning of differential responses of lysine and its metabolic product α-AA to high physiological insulin in IR compared to controls, we developed a kinetic model utilizing [α-15N1] lysine and [13C1] α-AA as tracers and measured the two tracers simultaneously in α-AA by innovative mass spectrometry. High insulin increased lysine conversion to α-AA in IR and controls but failed to normalize plasma lysine concentrations in IR due to a decrease in lysine metabolic clearance rate (MCR). In contrast, despite higher conversion rates of lysine to α-AA by high insulin, α-AA concentration decreased in IR because of the sustained greater MCR of α-AA. The abnormal AAs and metabolites, even while on high physiological insulin, could potentially explain many functional derangements in IR.

Amino Acid Content in the Muscles of the Red Deer (Cervus elaphus) from Three Types of Feeding Grounds

This study aimed to analyze the amino acid profile, with a particular focus on the nutritional value of the protein of the longissimus lumborum (LL) and the semimembranosus (SM) muscles of deer originating from three feeding grounds: forest (FFG); conventional (CFG) grounds; organic farm (OFG). This is the first time that deer from an organic farm feeding ground have been included in this study. The muscles were collected from 36 deer carcasses with equal proportions of sex and 31 months of age. This study demonstrated significantly higher essential amino acid (EAA) and non-essential amino acid (NEAA) contents in the muscles of deer from the FFG and CFG compared to the OFG. However, the EAA-to-NEAA ratio was significantly higher for the muscles of deer from the OFG. The muscles of the FFG and CFG deer were characterized by a higher concentration of lysine as well as acidic and tasty amino acids compared to the OFG deer, with the muscles of the latter exhibiting a higher percentage of branched-chain amino acids (BCAA). The results obtained can be used professionally by nutrition specialists in preventive and therapeutic diets and breeders to make decisions about farm location and deer feeding strategies.

Multi‐response kinetic study of Maillard reaction hazards in the glucose‐lysine model system

AbstractBACKGROUNDNε‐carboxymethyllysine (CML), Nε‐carboxyethyllysine (CEL) and α‐aminoadipic acid (AAA) are important foodborne hazards and their intake can cause a variety of diseases in humans. It is extremely important to investigate the formation mechanism of CML, CEL and AAA, as well as their association with each other when aiming to control their production.RESULTSA multi‐response kinetic model was developed within the glucose‐lysine Maillard reaction model system. The concentrations of glucose, lysine, glyoxal (GO), methylglyoxal (MGO), CML, CEL and AAA were quantified at different temperature (100–160 °C) and at different intervals (0–60 min). The experimental data were fitted to the proposed model to calculate kinetic parameters for the corresponding steps. The results indicated that the production of CML was primarily relied on the direct oxidative cleavage of the Amadori product, rather than the reaction between GO and Lys, whereas CEL and AAA were generated through the reaction of MGO with Lys. Significantly, the reaction between α‐dicarbonyl compounds and Lys preferentially generated CML and CEL, resulting in the lower concentrations of AAA compared to CML and CEL.CONCLUSIONThe multi‐response kinetic model developed in the present study can be applied well to the Maillard reaction. The relationship between the formation mechanisms of CML, CEL and AAA is also explained. © 2024 Society of Chemical Industry.

Comparative Effects of Efavirenz and Dolutegravir on Metabolomic and Inflammatory Profiles, and Platelet Activation of People Living with HIV: A Pilot Study.

Antiretroviral therapy (ART) has reduced the mortality and morbidity associated with HIV. However, irrespective of treatment, people living with HIV remain at a higher risk of developing non-AIDS-associated diseases. In 2019, the World Health Organization recommended the transition from efavirenz (EFV)- to dolutegravir (DTG)-based ART. Data on the impact of this transition are still limited. The current study therefore investigated the metabolic profiles, cytokine inflammatory responses, and platelet activation before and after the treatment transition. Plasma samples from nine virally suppressed adults living with HIV and sixteen healthy, HIV-uninfected individuals residing in Gauteng, South Africa were compared. Metabolite and cytokine profiles, and markers associated with platelet activation, were investigated with untargeted proton magnetic resonance metabolomics, multiplex suspension bead array immunoassays, and sandwich enzyme-linked immunosorbent assays, respectively. In those individuals with normal C-reactive protein levels, the transition to a DTG-based ART regimen resulted in decreased concentrations of acetoacetic acid, creatinine, adenosine monophosphate, 1,7-dimethylxanthine, glycolic acid, 3-hydroxybutyric acid, urea, and lysine. Moreover, increased levels of formic acid, glucose, lactic acid, myo-inositol, valine, glycolic acid, and 3-hydroxybutyric acid were observed. Notably, levels of interleukin-6, platelet-derived growth factor-BB, granulocyte-macrophage colony-stimulating factor, tumor necrosis factor-alpha, soluble cluster of differentiation 40 ligand, as well as regulated on activation, normal T-cell expressed and secreted (RANTES) reached levels close to those observed in the healthy control participants. The elevated concentration of macrophage inflammatory protein-1 alpha was the only marker indicative of elevated levels of inflammation associated with DTG-based treatment. The transition from EFV- to DTG-based regimens therefore appears to be of potential benefit with metabolic and inflammatory markers, as well as those associated with cardiovascular disease and other chronic non-AIDS-related diseases, reaching levels similar to those observed in individuals not living with HIV.

PSLBI-22 Identifying plasma metabolites influencing body weight in Salmonella challenged growing pigs: A machine learning approach

Abstract Body weight (BW) is an important component of pig productivity. Understanding the metabolic factors affecting growth rate is key to guiding nutritional strategies and bringing economic benefits to pig farms. Machine learning (ML) algorithms have been used to capture patterns in large datasets and predict animal production traits based on integrated information of performance data and blood records. However, utilizing ML models and metabolomic profiling to predict BW of pigs in small datasets with challenged animals has yet to be reported. Therefore, this study investigated use of plasma metabolites in predicting BW of pigs at the growing stage. This simulation used data from gilts (n = 40; BW = 25.6 ± 2.3 kg) raised over a 28-d trial. Plasma samples and BW were collected on d 0, 14, and 28 after 8 h of fasting. Ninety plasma metabolites were identified and quantified from an untargeted metabolomics assay. The development dataset included 30, and the validation dataset contained 10 unique animals with repeated measures in time. The metabolites were log-transformed, Pareto-scaled and missing values were imputed using the minimum nonzero value method. The BW prediction model was performed in R with the caret package. The optimal hyper-parameter configuration for the random forest and neural network algorithms was evaluated based on repeated cross-validation. The final model was the random forest composed of 400 trees with 45 randomly selected predictors. Model accuracy was estimated on repeated cross-validation with 10-folds and 5 repeats and compared with the validation set based on the coefficient of determination (R2), the root mean squared error (RMSE), and Pearson correlation (r). The metabolites with greater contribution with variable importance score above 10 to the model development were extracted. Aiming to understand differences in BW categories, the model response was visualized with an alluvial diagram for the 3 variables with the greatest metabolite importance, and BW was classified as high, medium, and low. The main metabolites driving BW were lysine, oleic acid, aminomalonic acid, myo-inositol, and linoleic acid. The RMSE after cross-validation was 7.22 kg of BW (r = 0.70), and R2 = 0.39. For pigs with a high BW, the predicted BW was explained by generally less plasmatic concentrations of lysine, oleic acid, and aminomalonic acid. Lysine is the main amino acid for muscle protein accretion, whereas oleic acid is for energy substrate. Aminomalonic acid is a metabolite resulting from glycine metabolism and is important in reversing oxidative damage caused by pathogens. Therefore, decreased plasma lysine, amino malonic acid, and oleic acid may indicate faster growth and lean deposition, leading to heavier BW in pigs. Using random forests helped to connect the plasma dynamics to BW and is a promising avenue to understand the main drivers in BW of group-housed pigs.

Genetic analysis of QTLs for lysine content in four maize DH populations

BackgroundLow levels of the essential amino acid lysine in maize endosperm is considered to be a major problem regarding the nutritional quality of food and feed. Increasing the lysine content of maize is important to improve the quality of food and feed nutrition. Although the genetic basis of quality protein maize (QPM) has been studied, the further exploration of the quantitative trait loci (QTL) underlying lysine content variation still needs more attention.ResultsEight maize inbred lines with increased lysine content were used to construct four double haploid (DH) populations for identification of QTLs related to lysine content. The lysine content in the four DH populations exhibited continuous and normal distribution. A total of 12 QTLs were identified in a range of 4.42–12.66% in term of individual phenotypic variation explained (PVE) which suggested the quantitative control of lysine content in maize. Five main genes involved in maize lysine biosynthesis pathways in the QTL regions were identified in this study.ConclusionsThe information presented will allow the exploration of candidate genes regulating lysine biosynthesis pathways and be useful for marker-assisted selection and gene pyramiding in high-lysine maize breeding programs.

Structural, techno‐functional and nutraceutical properties of lentil proteins – a concise review

SummaryLentil is one of the major pulses consumed in many parts of the world. Lentil proteins comprise primarily three fractions, viz. globulins, albumins and glutelins, each having distinct structural and functional characteristics. The secondary structure of lentil proteins is characterised by a predominance of β‐sheets, which occur in proportions up to 63% in the fractions. Protein isolates, in comparison, have up to 40% random coils, 38% sheets, 36% turns and 33% helix. Lentil proteins contain most essential amino acids, while albumins and glutelins have relatively higher content of lysine, methionine, histidine, threonine and branched‐chain amino acids. Amongst globulin proteins, vicilins have a more balanced amino acid composition than legumins. Lentil proteins also exhibit techno‐functional properties (foaming and emulsification, water and fat absorption and gelation) and may also serve as a potential source of active proteins/peptides, which make them an attractive alternative to conventional protein sources.

Manipulation impacts of jack mackerel meal in low fish meal diets on growth, feed availability, and biochemical composition of olive flounder (Paralichthys olivaceus) and economic analysis

AbstractManipulation effects of jack mackerel meal (JMM) in the low fish meal (FM) diets substituting 50% FM with meat meal (MM) on growth performance of olive flounder and economic analysis were determined. Seven experimental diets were created. The control (Con) diet contained 60% FM. In the other diets, 50% of the FM level used for the Con diet was substituted with MM, and then graded levels (0, 10, 20, 30, 40, and 50%) of JMM were included at the expense of FM, named the MJ0, MJ10, MJ20, MJ30, MJ40, and MJ50 diets, respectively. The experimental diets were distributed to triplicate groups of fish. A total of 525 fish was divided into 21 flow‐through tanks. Fish were hand‐fed to apparent satiation for 8 weeks. Weight gain, specific growth rate (SGR), and feed consumption of fish fed the Con diet were comparable with fish fed the MJ20, MJ30, MJ40, and MJ50 diets. Weight gain, SGR, and feed consumption of fish linearly improved with JMM inclusion levels in the low FM diets replacing 50% FM with MM. The strong correlation between isoleucine and lysine content among essential amino acids in the experimental diets versus weight gain, SGR, and feed consumption of olive flounder were observed. Dietary treatments did not influence feed utilization, chemical composition, and amino acid profiles of fish. Incorporated 20%–50% JMM as an effective feed attractant and enhancer in the low FM diets replacing 50% FM with MM achieved comparable weight gain, SGR, and feed consumption to fish fed a 60% FM‐based diet. Finally, the MJ50 diet led to the highest economic profit index (EPI) for farmers.

Characterization of Plant-Based Meat Treated with Hot Air and Microwave Heating.

Plant-based meat is growing globally due to health, environmental, and animal welfare concerns, though there is a need for quality improvements. This study assessed how different ratios of wheat gluten (WG) to soy protein isolate (SPI) and various baking methods-hot air (HA), microwave (MW), and a combination of both (HA-MW)-affect the physicochemical properties of plant-based meat. Increasing the SPI from 0% to 40% significantly enhanced lightness, hardness, chewiness, water-holding capacity, moisture content, and lysine (an essential amino acid) (p ≤ 0.05). Hardness and chewiness ranged from 4.23 ± 1.19 N to 25.90 ± 2.90 N and 3.44 ± 0.94 N to 18.71 ± 1.85 N, respectively. Baking methods did not affect amino acid profiles. Compared to HA baking, MW and HA-MW baking increased lysine content (561.58-1132.50 mg/100 g and 544.85-1088.50 mg/100 g, respectively) while reducing fat and carbohydrates. These findings suggest that a 40% SPI and 60% WG ratio with microwave baking (360 W for 1 min) optimizes plant-based meat, offering benefits to both consumers and the food industry in terms of health and sustainability.

Flour Fortification Using Lablab Purpureus Evaluation with a Biosensor.

Due to rapid metabolic and growth rates during the first two years of life, the nutritional needs of young children are high. Given the small portion sizes consumed by children between the ages of 6 and 24 months, it is necessary to improve diets to meet the nutritional needs of this age group. Therefore, the analysis of lysine content is an important parameter in the evaluation of enriched foods. The utilization of an enzymatic sensor employing lysine-α-oxidase (LOx) as a biorecognition element represents an alternative to the existing methods. This sensor was optimized for quantifying the lysine content in flour mixtures: Quinoa-Lablab purpureus rye - Lablab purpureus, and pole beans - Lablab purpureus, with a maximum ratio of 85g/100g. The addition of lablab purpureus significantly increased the lysine concentration in the enriched samples. When 30 percent was substituted in quinoa, it reached a 143 percent increase. And when 15 percent was substituted in the rye flour, the final concentration of this amino acid increased by 64 percent. In order to quantify the lysine concentration, it was necessary to optimize various parameters during the use of the sensor, e.g. a potentiometric signal was detected upon the depletion of oxygen present during the oxidation of lysine in the samples, and the sensor response was recorded at 2 s. This was possible due to the modification of the pH and the thickness of the membrane. The oxidation of lysine is catalyzed by LOx using molecular oxygen as the electron acceptor. The corresponding acidic compounds and hydrogen peroxide were formed in the reaction medium. It was possible to increase and verify the concentration of lysine in all the flours tested through the use of the biosensor, which turned out to be a valid method for controlling the nutritional quality of flours.

Lysine methylation: A strategy to improve in-cell NMR spectroscopy of proteins

BackgroundIn-cell NMR is a valuable technique for investigating protein structure and function in cellular environments. However, challenges arise due to highly crowded cellular environment, where nonspecific interactions between the target protein and other cellular components can lead to signals broadening or disappearance in NMR spectra. ResultsWe implemented chemical reduction methylation to selectively modify lysine residues on protein surfaces aiming to weaken charge interactions and recover obscured NMR signals. This method was tested on six proteins varying in molecular size and lysine content. While methylation did not disrupt the protein's native conformation, it successful restored some previously obscured in-cell NMR signals, particularly for proteins with high isoelectric points that decreased post-methylation. SignificanceThis study affirms lysine methylation as a feasible approach to enhance the sensitivity of in-cell NMR spectra for protein studies. By mitigating signal loss due to nonspecific interactions, this method expands the utility of in-cell NMR for investigating proteins in their natural cellular environment, potentially leading to more accurate structural and functional insights.

Taurine drives body protein renewal and accretion in beef steers

The aims of the present study were to investigate the effects of dietary supplementation with rumen-protected taurine (RPT) on whole-body protein turnover, plasma metabolomics, and whole blood cell transcriptomics in steers. Eight steers, averaging 220 ± 3.26 (mean ± SD) kg of liveweight, were allocated in a replicate 4 × 4 Latin square design. The experimental treatments consisted of four levels of RPT supplementation: 0, 25, 50, and 75 g RPT per day, added to a basal diet. The results showed that supplementation with RPT linearly decreased the fecal nitrogen (N) excretion (P = 0.001) and the 15N fractional recovery rate (P = 0.047), while it linearly increased the urinary excretion of taurine (P = 0.045) as well as the average daily weight gain (P = 0.003), protein synthesis (P < 0.001), protein degradation (P < 0.001) and the whole-body protein turnover (P < 0.001). Supplementation with RPT linearly increased the plasma concentrations of growth hormone (P = 0.005) and quadratically affected the plasma concentration of insulin-like growth factor-1 (P = 0.013), and it linearly decreased the plasma concentration of albumin (P = 0.022). Supplementation with RPT altered the whole blood cell mRNA expression and upregulated the expressions of the marker genes, including RPS6KB1, PRSS42, COL1A2, ENSBTAG00000013055 and ENSBTAG00000038159 which are related to protein metabolism. The plasma metabolome profiling indicated that supplementation with RPT upregulated the plasma concentrations of taurine, lysine and methionine. The experiment revealed the impact and the mechanisms of taurine on driving whole-body protein turnover and protein accretion in steers. Two novel marker genes which could be related to body protein degradation in steers were identified.

Principles of rye breeding for low content of water-soluble pentosans in grain

Winter rye is the second cereal crop after wheat. Rye exceeds other cereals in terms of nutritional value due to the high content of lysine, methionine, valine, as well as the balance of other essential amino acids in its protein. The direct use of baking rye grain as an animal feed is limited by the presence of water-soluble pentosans (arabinoxylans) in it. Therefore, the creation of low-pentosan rye with highly nutritious grain is a very perspective direction in the grain feed cultivar breeding. Under the leadership and with direct participation of Vladimir D. Kobylyansky, a technology for breeding multiple-use low-pentosan rye was worked out at the N.I. Vavilov VIR in 2004-2021. A relationship between the low pentosan content and grain coat thinness has been revealed. For the first time, an effective method of low-pentosan genotypes identification by selecting thin-coat grains has been developed. This method was used to study 562 accessions from the VIR collection represented by cultivar populations, weedy and wild rye. It has been established that the number of thin-coat grains in a sample varies from 12 to 70%, depending on the accession. Varieties with the highest frequencies of low-pentosan genotypes can be used as initial material for breeding. The dependence of low content of water-soluble pentosans in grains on the expression of recessive alleles of the gene/genes responsible for the manifestation of the trait has been revealed. To create grain feed cultivars, it is proposed to use the method of cumulative intrapopulation crosses and the method of pairwise cross-pollinations of the plants with indicator ears. As a result, new cultivar populations of low-pentosan rye for universal use have been created, namely ‘Vavilovskayaʼ, ‘Bereginyaʼ, ‘Podarokʼ, ‘Yantarnayaʼ, ‘Krasnoyarskaya Universalnayaʼ, ‘Novaya Eraʼ, and ‘Argaʼ. These cultivars are characterized by a low, as in wheat, genetically determined content of pentosans. They have been evaluated in the main rye growing regions, tested as raw material for fodder production and bread baking, and found to match the previously released commercial (bread) cultivars in terms of yield. The baking properties of new cultivars do not exceed those of bread rye. The use of low-pentosan cultivars in animal diets eliminates the problem that exists when feeding them with bread rye grain. These cultivars have no analogs in the world; they are listed in the State Register for Selection Achievements Admitted for Usage (2023).