Incorporation Of Lysine Research Articles

Effects of rumen-protected methionine and lysine on antioxidant status and lactationperformance in crossbred dairy cattle during transition

Dairy cows undergoing the transition phase often face nutritional challenges, impacting their antioxidant status and lactational performance. To address these challenges, the incorporation of rumen-protected methionine and lysine in the diet has emerged as a strategic intervention.Twelve crossbred cows inthe transition period were randomly divided into two groups of six animals. The control group and treatment group were fed with a standard diet (ICAR, 2013) while the treatment group was supplemented with rumen-protected methionine and lysine. Throughout the trial period, all the animals were subjected to consistent management and feeding conditions.Glutathione peroxide(GPx)levels exhibited a statistically significant difference between groups, with the treatment consistently showing higher GPx levels, indicating an improvement in antioxidant capacity, where it helps regulate systemic oxidative stress.The recorded milk yield data was utilized to compute the daily milk production for each individual for the experimental period. Milk yield remained unaffected, but the treatment group consistently exhibited higher milk yield, suggesting positive influences on postpartum lactation performance. Keywords: Rumen-protectedmethionine, rumen-protectedlysine,transition period, antioxidant status

Insight into the mechanism of the aggregation behavior of wheat protein modulated by l-lysine under microwave irradiation.

This study explored the mechanism of l-lysine intervention in wheat gluten protein (WG) gel formation under a microwave (MW) field. The results showed that the MW treatment had higher ζ-potential values at the same heating rate. After adding l-lysine, the solution conductivity and dielectric loss were significantly increased. Moreover, the WG gel strength enhanced 4.40% under the MW treatment. The Fourier spectra showed that the α-helix content was decreased 13.78% with the addition of lysine. The ultraviolet absorption spectra and fluorescence spectra indicated that MW irradiation impacted the interactions between WG molecules more effectively than the water bath heating, promoting the denaturation and unfolding of the protein structure. In addition, scanning electron microscopy analysis showed that the incorporation of lysine promoted an ordered network structure formation of the protein, which enhanced the gel properties. This indicated that the zwitterion of l-lysine played a regulatory role in the aggregation of proteins in the MW field.

Engineering Enhanced Antimicrobial Properties in α-Conotoxin RgIA through D-Type Amino Acid Substitution and Incorporation of Lysine and Leucine Residues.

Antimicrobial peptides (AMPs), acknowledged as host defense peptides, constitute a category of predominant cationic peptides prevalent in diverse life forms. This study explored the antibacterial activity of α-conotoxin RgIA, and to enhance its stability and efficacy, D-amino acid substitution was employed, resulting in the synthesis of nine RgIA mutant analogs. Results revealed that several modified RgIA mutants displayed inhibitory efficacy against various pathogenic bacteria and fungi, including Candida tropicalis and Escherichia coli. Mechanistic investigations elucidated that these polypeptides achieved antibacterial effects through the disruption of bacterial cell membranes. The study further assessed the designed peptides' hemolytic activity, cytotoxicity, and safety. Mutants with antibacterial activity exhibited lower hemolytic activity and cytotoxicity, with Pep 8 demonstrating favorable safety in mice. RgIA mutants incorporating D-amino acids exhibited notable stability and adaptability, sustaining antibacterial properties across diverse environmental conditions. This research underscores the potential of the peptide to advance innovative oral antibiotics, offering a novel approach to address bacterial infections.

Enhanced proton conductivity in a Cu-BTC thin-film membrane through lysine incorporation and a mixed matrix membrane

Preparation of a proton-conductive membrane with abundant proton hopping pathways.

Fabrication of highly permeable thin-film composite forward osmosis membrane using poly-l-lysine as an additive in polysulfone substrate

Forward osmosis (FO) has received considerable interest for water and energy-related applications in recent years. However, FO has not been commercialized yet because of a few reasons. The lack of a high-performance FO membrane is one of the important barriers. To overcome this issue, a novel high-performance thin-film composite (TFC) membrane was successfully fabricated via interfacial polymerization with poly-L-lysine incorporated polysulfone substrate (PSf). Compared to the pristine PSf substrate, the incorporation of lysine (ranging 1 – 15 wt.%) meaningfully alternates the substrates chemical structure, porosity, contact angle, and morphology leading to an enhancement of the lysine -TFC membranes performance. The results showed that the new substrates with higher porosity, more hydrophilic, and smaller in pore size after the introduction of L-lysine. The membrane achieved the highest FO water flux at 15% concentration of lysine and the maximum FO water flux was 35 L/m2.h (LMH) with a comparable specific salt flux (Js/Jw) of 0.002 g/L in the active layer facing the feed side (AL-FS) when 1M NaCl was applied as draw solution. The water flux was increased with increasing concentration of lysine. The addition of poly-L-Lysine in casting solution resulted in a more porous and hydrophilic support layer.

Engineering SHP2 Phosphatase for Optical Control.

Signal transduction pathways are responsible for maintaining cellular functions, including proliferation, differentiation, apoptosis, and cell cycle progression. These pathways are maintained through the propagation of phosphorylation signals by protein kinases, as well as the removal of phosphorylation signals by protein phosphatases. Depending on the context, post-translational modification could have either a positive or negative effect on a signaling pathway. Intricate networks of positive and negative regulators offer a challenging target for the dissection of cell signaling mechanisms, particularly regarding the more subtle dampening of signal transduction through phosphatases. We report the development of two complimentary methods for the optical control of a complex phosphatase: SH2 domain-containing protein tyrosine phosphatase-2 (SHP2). We investigated controlling the catalytic function of SHP2 through (1) site-specific incorporation of a caged tyrosine for light activation of catalytic activity for the control of an essential substrate binding residue and (2) site-specific incorporation of a caged lysine at a conserved residue within an allosteric pocket for the control of SHP2 binding partner docking sites. These methods are generalizable to proteins bearing either a protein tyrosine phosphatase (PTP) catalytic domain or an SH2 domain, including SHP1, PTP family phosphatases, and a diverse range of SH2 domain-containing proteins.

Effect of Dietary Lysine and Methionine Supplementation on the Growth and Physiological Responses of Pearlspot Fingerlings, Etroplus suratensis

Background: Successful and sustainable culture of finfish and shellfish depends on the use of nutritionally balanced, low-cost and eco-friendly feeds. This experiment was conducted to evaluate the effect of dietary supplementation of lysine and methionine on the growth and physiological responses of juvenile pearlspot, Etroplus suratensis. Methods: Fingerlings with an average initial body weight of 8.7±0.04 g were distributed to the 300 L FRP tank (n=30 pieces/tank). The pearl spot fingerlings were fed with isonitrogenous (25% Crude protein) feeds supplemented with methionine (1.8, 2.2 and 2.6 g/100 g of diet) and lysine (0.5, 0.9 and 1.3 g/100 g of diet). The growth performance and physiological response of the fishes were assessed. The feeding trial was conducted for a period of 60 days. Result: The methionine supplemented diets at 2.2 g/100 g (T2) and Lysine supplemented diet at 0.9 g/100 g (T5) yielded the best results within the treated groups in terms of average body weight gain, FCR (feed conversion ratio), SGR (specific growth rate), PER (protein efficiency ratio) and FER (feed efficiency ratio). The maximum mean body weight gain recorded in methionine supplemented diet was 20.68±0.20 g in T2 and the maximum mean body weight gain recorded in lysine supplemented diet was 19.6±0.15 g in T5. The mean body weight gain in control was recorded as 12.12±0.20 g. The present study revealed that methionine incorporation at 2.2 g/100 g (T2) and lysine incorporation at 0.9 g/100 g (T5) resulted in better growth performance of the pearl spot Etroplus suratensis fingerlings. Results of challenge tests confirmed that V. anguillarum could act as a primary pathogen for pearlspot reared in freshwater. In the present study, the Hb, RBC, MCV, MCH and MCHC were also affected by dietary methionine and lysine supplementation and were found significantly (p less than 0 .05) higher in fish fed methionine at 2.2% and lysine at 0.9% of diet, indicating that dietary methionine and lysine supplementation activates immune response and promotes fish health. Second-order polynomial regression analysis of weight gain against dietary methionine and lysine levels indicated that the optimum dietary methionine and lysine requirement for maximum growth and feed utilization of pearlspot fingerlings was methionine at 2.2% and lysine at 0.9%.

Excessive Increase in the Optical Band Gap of Near‐Infrared Semiconductor Lead (II) Sulfide via the Incorporation of Amino Acids

AbstractIncorporation of organic molecules into the crystal lattice of biominerals is one of Nature's main strategies to modify the structure, morphology, and specific physical properties of the mineral host. Inspired by this biostrategy, it is shown that several semiconductors, whose band gaps are in the ultraviolet or visible absorption spectrum, can incorporate individual amino acids (AAs) into their crystalline structures. Interestingly, such incorporation is accompanied by an increase in the optical band gap of semiconductor hosts, resulting from an internal quantum confinement effect. In this work, this bioinspired route of band gap tuning is applied for the first time to a semiconductor with a near‐infrared (NIR) band gap. Indeed individual AAs are found to become incorporated into the crystalline structure of lead (II) sulfide (PbS). It is shown that this incorporation induces an expansion of the PbS unit cell as well as changes in the morphology. Moreover, an unprecedented increase of up to 40–50% in the optical band gap is observed in the case of cysteine and lysine incorporation.

Practical application of the ideal protein concept in pigs

Objective: To determine the importance of the formulation of “ideal protein” diets for starting-growing pigs. Design/methodology/approach: A bibliographic review of the concept of ideal protein and low-protein in pig diets was carried out to determine their practical application in commercial production. Results: Low-protein diets in pig production are an environmentally friendly strategy. The 3 percentage units of reduction in CP is the maximum level, when only crystalline lysine, methionine, threonine, and tryptophan are available. However, when there is a greater number of synthetic amino acids, the reduction in CP can range from 4 to 5 percentage units. Study limitations/implications: Market conditions allow the incorporation of lysine, methionine, threonine, and tryptophan into the diet. Potentially, owing to its availability and price, valine could be considered as part of commercial diets in a short time. However, the inclusion of other AA is not currently viable, as a result of their low availability and high market price. Findings/conclusions: Low-protein diets should be used in pig production, since they maintain or improve the productive variables and reduce the environmental impact, as a result of the reduction of nitrogen excretion to the environment

Stable Isotope Labeling of Amino Acids in Flies (SILAF) Reveals Differential Phosphorylation of Mitochondrial Proteins Upon Loss of OXPHOS Subunits

Drosophila melanogaster has been a workhorse of genetics and cell biology for more than a century. However, proteomic-based methods have been limited due to the complexity and dynamic range of the fly proteome and the lack of efficient labeling methods. Here, we advanced a chemically defined food source into direct stable-isotope labeling of amino acids in flies (SILAF). It allows for the rapid and cost-efficient generation of a large number of larvae or flies, with full incorporation of lysine-[13C6] after six labeling days. SILAF followed by fractionation and enrichment gave proteomic insights at a depth of 7196 proteins and 8451 phosphorylation sites, which substantiated metabolic regulation on enzymatic level. We applied SILAF to quantify the mitochondrial phosphoproteome of an early-stage leucine-rich PPR motif-containing protein (LRPPRC)-knockdown fly model of mitochondrial disease that almost exclusively affects protein levels of the oxidative phosphorylation (OXPHOS) system. While the mitochondrial compartment was hypo-phosphorylated, two conserved phosphosites on OXPHOS subunits NDUFB10 and NDUFA4 were significantly upregulated upon impaired OXPHOS function. The ease and versatility of the method actuate the fruit fly as an appealing model in proteomic and posttranslational modification studies, and it enlarges potential metabolic applications based on heavy amino acid diets.

Bioinspired Molecular Bridging in a Hybrid Perovskite Leads to Enhanced Stability and Tunable Properties

AbstractHybrid perovskites demonstrate high potential in optoelectronic applications. Their main drawback is their low stability under humid conditions. In this paper, one of nature's strategies is implemented—the incorporation of amino acids into the crystal lattice—in order to improve the stability of methylammonium lead bromide (MAPbBr3) in water, and to tune its structure, as well as its optical and thermal properties. The amino acid lysine, which possesses two NH3+ groups, is incorporated into the hybrid unit cell, by substituting two methylammonium ions and serves as a “molecular bridge”. This incorporation induces a decrease in the lattice parameter of the host, accompanied with an increase in its bandgap and noticeable changes in its morphology. Furthermore, a substantial decrease in the thermal expansion coefficient of MAPbBr3 and a shift of its cubic‐to‐tetragonal phase transformation temperature are observed. Two different modes of incorporation are identified, which depend on the conditions of crystallization. These modes dictate the level of lysine incorporation and the magnitude of MAPbBr3 bandgap changes. Notably, lysine incorporation strongly increases the perovskite stability in water. This study demonstrates a unique and promising approach to tune the properties and improve the stability of hybrid perovskites via this novel bioinspired route.

A methylated lysine is a switch point for conformational communication in the chaperone Hsp90

Methylation of a conserved lysine in C-terminal domain of the molecular chaperone Hsp90 was shown previously to affect its in vivo function. However, the underlying mechanism remained elusive. Through a combined experimental and computational approach, this study shows that this site is very sensitive to sidechain modifications and crucial for Hsp90 activity in vitro and in vivo. Our results demonstrate that this particular lysine serves as a switch point for the regulation of Hsp90 functions by influencing its conformational cycle, ATPase activity, co-chaperone regulation, and client activation of yeast and human Hsp90. Incorporation of the methylated lysine via genetic code expansion specifically shows that upon modification, the conformational cycle of Hsp90 is altered. Molecular dynamics simulations including the methylated lysine suggest specific conformational changes that are propagated through Hsp90. Thus, methylation of the C-terminal lysine allows a precise allosteric tuning of Hsp90 activity via long distances.

Irp2 regulates insulin production through iron-mediated Cdkal1-catalyzed tRNA modification

Regulation of cellular iron homeostasis is crucial as both iron excess and deficiency cause hematological and neurodegenerative diseases. Here we show that mice lacking iron-regulatory protein 2 (Irp2), a regulator of cellular iron homeostasis, develop diabetes. Irp2 post-transcriptionally regulates the iron-uptake protein transferrin receptor 1 (TfR1) and the iron-storage protein ferritin, and dysregulation of these proteins due to Irp2 loss causes functional iron deficiency in β cells. This impairs Fe–S cluster biosynthesis, reducing the function of Cdkal1, an Fe–S cluster enzyme that catalyzes methylthiolation of t6A37 in tRNALysUUU to ms2t6A37. As a consequence, lysine codons in proinsulin are misread and proinsulin processing is impaired, reducing insulin content and secretion. Iron normalizes ms2t6A37 and proinsulin lysine incorporation, restoring insulin content and secretion in Irp2−/− β cells. These studies reveal a previously unidentified link between insulin processing and cellular iron deficiency that may have relevance to type 2 diabetes in humans.

Effect of lysine incorporation, annealing and heat moisture treatment alone and in combination on the physico‐chemical, retrogradation, rheological properties and in vitro digestibility of kithul (Caryota urens L.) starch

SummaryPhysico‐chemical, retrogradation, rheological properties and in vitro digestibility of lysine incorporated kithul starch modified by annealing, heat moisture treatment and its combinations were studied. LS‐AHMT (annealed‐heat moisture treated lysine incorporated kithul starch) exhibited lowest amylose leaching. LS‐AHMT showed significantly (P ≤ 0.05) higher relative crystallinity. LS‐ANS (annealed lysine incorporated kithul starch), LS‐HMT (heat moisture treated lysine incorporated kithul starch) and LS‐AHMT formed more weak gel by the effect of annealing, heat moisture treatment and its combination. LS‐AHMT showed lowest pasting viscosities, G′ and G″ values among the modified kithul starch, which indicates its lower retrogradation properties. In vitro digestibility of kithul starch decreased after modifications and LS‐ANS, LS‐HMT and LS‐AHMT showed significantly higher resistant starch content. The current study showed that annealing, heat moisture treatment and its combination on NS‐LS (lysine incorporated kithul starch) effectively modified kithul starch properties.

Optical control of protein phosphatase function

Protein phosphatases are involved in embryonic development, metabolic homeostasis, stress response, cell cycle transitions, and many other essential biological mechanisms. Unlike kinases, protein phosphatases remain understudied and less characterized. Traditional genetic and biochemical methods have contributed significantly to our understanding; however, these methodologies lack precise and acute spatiotemporal control. Here, we report the development of a light-activated protein phosphatase, the dual specificity phosphatase 6 (DUSP6 or MKP3). Through genetic code expansion, MKP3 is placed under optical control via two different approaches: (i) incorporation of a caged cysteine into the active site for controlling catalytic activity and (ii) incorporation of a caged lysine into the kinase interaction motif for controlling the protein-protein interaction between the phosphatase and its substrate. Both strategies are expected to be applicable to the engineering of a wide range of light-activated phosphatases. Applying the optogenetically controlled MKP3 in conjunction with live cell reporters, we discover that ERK nuclear translocation is regulated in a graded manner in response to increasing MKP3 activity.

342-LB: Iron Regulatory Protein 2 Regulates Proinsulin Production in Pancreatic Beta Cells through Iron-Dependent Cdkal1-Catalyzed tRNA Modification

Iron regulatory protein 2 (Irp2) is a key regulator of cellular iron metabolism in vertebrates. Irp2 controls the post-transcriptional expression of the iron-uptake protein transferrin receptor 1 (TfR1) and the iron-storage protein ferritin. Here we show that Irp2-/-mice develop diabetes characterized by glucose intolerance and impaired glucose-stimulated insulin secretion from pancreatic β-cells. Impaired glucose-stimulated insulin secretion in Irp2-/-β-cells is not due to insulin resistance but rather to a reduction in insulin stores caused by impaired proinsulin processing. Loss of Irp2 reduces TfR1 expression and iron content, and increases ferritin expression and iron sequestration causing cellular iron deficiency that impairs mitochondrial Fe-S cluster biosynthesis. This in turn reduces the function of Cdk5-regulated subunit-associated protein 1 like (Cdkal1), a 4Fe-4S cluster enzyme that catalyzes the 2-methythio (ms) modification of t6A37 of tRNALys(UUU)to ms2t6A37, which is critical for efficient translation of lysine codons in proinsulin. Irp2-deficient β cells show reduced ms2t6A37 levels and lysine incorporation into proinsulin. Increasing cellular iron content in Irp2-deficient β cells normalizes mitochondrial function, ms2t6A37 levels, proinsulin and insulin content, and insulin secretion. These study reveals a previously unidentified link between insulin processing and cellular iron homeostasis, and show that Irp2 is required for normal β cell function and whole body glucose homeostasis. Disclosure M.C. Ferreira dos Santos: None. M. Rajan: None. E. Leibold: None. Funding American Diabetes Association (1-18-PMF-020 to M.C.F.D.S.); National Institute of Diabetes and Digestive and Kidney Diseases

Re-evaluation of cyanophycin synthesis in Corynebacterium glutamicum and incorporation of glutamic acid and lysine into the polymer.

Corynebacterium glutamicum was only examined in the early 2000s as a possible microorganism for the production of the polyamide cyanophycin (multi-L-arginyl-poly-[L-aspartic acid], CGP). CGP is a potential precursor for the synthesis of polyaspartic acid and CGP-derived dipeptides which may be of use in peptide-based clinical diets, as dietary supplements, or in livestock feeds. In the past, C. glutamicum was disregarded for CGP production due to low CGP contents and difficulties in isolating the polymer. However, considering recent advances in CGP research, the capabilities of this organism were revisited. In this study, several cyanophycin synthetases (CphA) as well as expression vectors and cultivation conditions were evaluated. The ability of C. glutamicum to incorporate additional amino acids such as lysine and glutamic acid was also examined. The strains C. glutamicum pVWEx1::cphAΔ1 and C. glutamicum pVWEx1::cphABP1 accumulated up to 14% of their dry weight CGP, including soluble CGP containing more than 40mol% of the alternative side-chain amino acid lysine. The soluble, lysine-rich form of the polymer was not detected in C. glutamicum in previous studies. Additionally, an incorporation of up to 6mol% of glutamic acid into the backbone of CGP synthesized by C. glutamicum pVWEx1::cphADh was detected. The strain accumulated up to 17% of its dry weight in soluble CGP. Although glutamic acid had previously been found to replace arginine in the side chain, this is the first time that glutamic acid was found to substitute aspartic acid in the backbone.

Modulating pH through lysine integrated dental adhesives

ObjectivesThe objective of this study was to explore the effect of lysine integration to dental adhesives with respect to the polymerization kinetics, neutralization capacities in the acidic microenvironment, dynamic mechanical properties, and thermal properties. Materials and methodLysine was incorporated into liquid resin formulations at 2.5 and 5.0wt % with additional water/ethanol co-solvents. The co-monomer system contained 2-hydroxyethyl-methacrylate (HEMA) and Bisphenol A glycerolate dimethacrylate (BisGMA) with a mass ratio of 45/55. The kinetics of photopolymerization, neutralization capacities, lysine-leaching, dynamic mechanical properties and thermal properties of the control and experimental adhesives were analyzed. ResultsThe degree of conversion of the experimental adhesive was increased substantially at 2.5wt% lysine as compared to the control. The experimental polymers provided acute neutralization of the acidic microenvironment. Approximately half of the lysine was released from the polymer network within one month. Under dry conditions and physiologic temperatures, the incorporation of lysine did not compromise the storage modulus. Comparison of the thermal properties suggests that the more compact structure of the control adhesive inhibits movement of the polymer chains resulting in increased Tg. SignificanceIncorporating lysine in the adhesive formulations led to promising results regarding modulating pH, which may serve as one aspect of a multi-spectrum approach for enhancing the durability of composite restorations. The results provide insight and lay a foundation for incorporating amino acids or peptides into adhesive formulations for pH modulation or desired bioactivity at the interfacial margin between the composite and tooth.

Determinants and Regulation of Protein Turnover in Yeast.

Protein turnover maintains the recycling needs of theproteome, and its malfunction has been linked to aging and age-related diseases. However, not allproteins turnover equally, and the factors that contribute to accelerate or slow down turnover are mostly unknown. We measured turnover rates for 3,160 proteins in exponentially growing yeast and analyzed their dependence on physical, functional, and genetic properties. We found that functional characteristics, including protein localization, complex membership, and connectivity, have greater effect on turnover than sequence elements. We also found that protein turnover and mRNA turnover are correlated. Analysis under nutrient perturbation and osmotic stress revealed that protein turnover highly depends on cellular state and is faster when proteinsare being actively used. Finally, stress-induced changes in protein and transcript abundance correlated with changes in protein turnover. This study provides a resource of protein turnover rates and principles to understand the recycling needs of the proteome under basal conditions and perturbation.

Combined effect of aminoacids and microbial transglutaminase on gelation of low salt surimi content under high pressure processing

Abstract The paper examines the effect of High Pressure Processing (HPP) (300 MPa), the incorporation of microbial transglutaminase (MTGase) and the addition of different additives such as lysine and cystine, as potential enhancers of low-salt (0.3%) surimi gel. Effects on myosin as the molecule responsible for gelation was monitored by Fourier transform infrared spectroscopy, Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE), and dynamic rheometry measurements. The effects on physicochemical properties of surimi gels were determined by Folding and Puncture tests and water holding capacity. Results indicated an increase in β-sheet when HPP was applied or additives added (cystine and lysine), especially when samples are treated with MTGase. Protein aggregation due to HPP and the additives resulted in lower myosin heavy chain (MHC) band density in the SDS–PAGE. Rheometry measurements indicated that MTGase activity was prompted by the incorporation of cystine and lysine in the absence of HPP. Also, HPP assisted gelation, resulting in improved mechanical properties of the gels. Samples containing additives, with or without HPP, exhibited the highest Folding test scores, indicating greater network flexibility. Lastly, water binding capacity was also enhanced by both additives and HPP. Industrial relevance The industrial relevance of the present work is focused on the appropriated gelation of myofibrillar proteins which is an essential step in the elaboration of surimi-based products. Sodium chloride has an important role in that fact inducing protein unfolding and solubilization. The reduction in NaCl content, following the NAOS strategy, required the application of different technologies to facilitate surimi adequate gelation. High-pressure processing has been commonly used as an innovative technology to prolong shelf life but it can be successfully used to induce proteins gelation. Due to that ability, the use of high pressure on surimi-based products result an interesting tool to facilitate surimi gelation. The use of Microbial transglutaminase (MTGase) alone or in combination with some aminoacids such as lysine and cystine can significantly improve surimi gelation added in a very small proportion.