Concentrations Of L-alanine Research Articles

1H-NMR Analysis of Amino Acid Metabolism in Cerebrospinal Fluid of Dogs with Neurological Distemper

Abstract Canine Distemper Virus (CDV) infection causes a multifocal demyelinating progressive disease within the central nervous system (CNS) that results in wide range of neurological symptoms. Pathological changes in the brain or CNS could be observed by analyzing cerebrospinal fluid (CSF). Therefore, this study aimed to investigate the concentrations of amino acids in the CSF of dogs with neurological form of CDV infection, and to identify amino acids as markers that can be used in the diagnosis, pathogenesis, and treatment of the disease. Heathy dogs (n=6), confirmed by clinical and laboratory examinations (Healthy group), and CDV-infected dogs (n=10) with neurological symptoms, confirmed by clinical, laboratory, and rapid diagnostic test kits (Distemper group), were used. CSF samples were obtained with an appropriate method and were subjected to 1H-NMR analysis. Identification was made on 10, whereas quantification on 8 amino acids. L-tyrosine, L-phenylalanine, L-threonine, and L-alanine concentrations were significantly lower, while L-histidine and L-tryptophan were significantly higher than the Healthy group (p<0.05). It was concluded that L-tyrosine could be used for assessing mental status changes, L-phenylalanine for evaluating neuroprotective responses, L-threonine and L-histidine for gauging the extent of neurodegeneration and ventricular degeneration, L-alanine for exploring cellular stress and energy metabolism, and L-tryptophan for understanding the process of sympathetic nervous system activation.

Control of three-carbon amino acid homeostasis by promiscuous importers and exporters in Bacillus subtilis: role of the "sleeping beauty" amino acid exporters.

The Gram-positive model bacterium Bacillus subtilis can acquire amino acids by import, de novo biosynthesis, or degradation of proteins and peptides. The accumulation of several amino acids inhibits the growth of B. subtilis, probably due to misincorporation into cellular macromolecules such as proteins or peptidoglycan or due to interference with other amino acid biosynthetic pathways. Here, we studied the adaptation of B. subtilis to toxic concentrations of the three-carbon amino acids L-alanine, β-alanine, and 2,3-diaminopropionic acid, as well as the two-carbon amino acid glycine. Resistance to the non-proteinogenic amino acid β-alanine, which is a precursor for coenzyme A biosynthesis, is achieved by mutations that either activate a cryptic amino acid exporter, AexA (previously YdeD), or inactivate the amino acid importers AimA, AimB (previously YbxG), and BcaP. The aexA gene is very poorly expressed under most conditions studied. However, mutations affecting the transcription factor AerA (previously YdeC) can result in strong constitutive aexA expression. AexA is the first characterized member of a group of amino acid exporters in B. subtilis, which are all very poorly expressed. Therefore, we suggest to call this group "sleeping beauty amino acid exporters." 2,3-Diaminopropionic acid can also be exported by AexA, and this amino acid also seems to be a natural substrate of AerA/AexA, as it can cause a slight but significant induction of aexA expression, and AexA also provides some natural resistance toward 2,3-diaminopropionic acid. Moreover, our work shows how low-specificity amino acid transporters contribute to amino acid homeostasis in B. subtilis.IMPORTANCEEven though Bacillus subtilis is one of the most-studied bacteria, amino acid homeostasis in this organism is not fully understood. We have identified import and export systems for the C2 and C3 amino acids. Our work demonstrates that the responsible amino acid permeases contribute in a rather promiscuitive way to amino acid uptake. In addition, we have discovered AexA, the first member of a group of very poorly expressed amino acid exporters in B. subtilis that we call "sleeping beauty amino acid exporters." The expression of these transporters is typically triggered by mutations in corresponding regulator genes that are acquired upon exposure to toxic amino acids. These exporters are ubiquitous in all domains of life. It is tempting to speculate that many of them are not expressed until the cells experience selective pressure by toxic compounds, and they protect the cells from rare but potentially dangerous encounters with such compounds.

Systems engineering of Escherichia coli for high-level l-alanine production

l-alanine is a critical natural amino acid that is widely used in the food, pharmaceutical, and personal care industries. However, low titer and long fermentation period limits the industrial viability of l-alanine production. In this study, we engineered a microbial cell factory for efficient l-alanine synthesis using a variety of metabolic engineering strategies. Initially, l-alanine was biosynthesized through the heterologous introduction of alanine dehydrogenase from Geobacillus stearothermophilus. Thereafter, the l-alanine biosynthetic pathway and transport module were modified to improve its titers. Furthermore, a dynamic response system was constructed based on the l-alanine-driven PAla-7 promoter to regulate the tolerance target BetT expression and enhance the tolerance of Escherichia coli to high l-alanine concentrations. Finally, the resultant strain E. coli W-PAla-7-BetT could produce 134.5 g/L of l-alanine in 24 h in a 5-L bioreactor, with 5.6 g/L/h of productivity, which is the highest productivity reported to date. Our findings may help in constructing high-performance microbial cell factories for the production of l-alanine and other valuable chemicals.

Differences in the regulatory strategies of marine oligotrophs and copiotrophs reflect differences in motility.

Aquatic bacteria frequently are divided into lifestyle categories oligotroph or copiotroph. Oligotrophs have proportionately fewer transcriptional regulatory genes than copiotrophs and are generally non-motile/chemotactic. We hypothesized that the absence of chemotaxis/motility in oligotrophs prevents them from occupying nutrient patches long enough to benefit from transcriptional regulation. We first confirmed that marine oligotrophs are generally reduced in genes for transcriptional regulation and motility/chemotaxis. Next, using a non-motile oligotroph (Ca. Pelagibacter st. HTCC7211), a motile copiotroph (Alteromonas macleodii st. HOT1A3), and [14 C]l-alanine, we confirmed that l-alanine catabolism is not transcriptionally regulated in HTCC7211 but is in HOT1A3. We then found that HOT1A3 took 2.5-4min to initiate l-alanine oxidation at patch l-alanine concentrations, compared to <30 s for HTCC7211. By modelling cell trajectories, we predicted that, in most scenarios, non-motile cells spend <2min in patches, compared to >4 min for chemotactic/motile cells. Thus, the time necessary for transcriptional regulation to initiate prevents transcriptional regulation from being beneficial for non-motile oligotrophs. This is supported by a mechanistic model we developed, which predicted that HTCC7211 cells with transcriptional regulation of l-alanine metabolism would produce 12% of their standing ATP stock upon encountering an l-alanine patch, compared to 880% in HTCC7211 cells without transcriptional regulation.

METABOLOMIC PROFILES FOR THE EXPLORATION OF BIOMARKERS IN SEVERE SARCOPENIA AMONG OLDER MEN

Abstract The pathophysiology of sarcopenia is complex and multifactorial; however, it has not been fully elucidated. This preliminary study explored novel biomarkers of severe sarcopenia through a metabolomic analysis of plasma metabolites in community-dwelling older men. Twenty older men (mean age: 81.9±2.8 years) were randomly selected from the Korean Frailty and Aging Cohort Study. Participants with severe sarcopenia were compared to healthy, age-, and body mass index-matched controls (n = 10 each). Severe sarcopenia was diagnosed using the Asian Working Group for Sarcopenia 2019 criteria. Non-targeted metabolomic profiling of plasma metabolites was performed using capillary electrophoresis time-of-flight mass spectrometry. Among the 191 plasma metabolic peaks, 10 metabolites differed significantly between healthy controls and participants with severe sarcopenia. The plasma concentrations of l-alanine, homocitrulline, n-acetylserine, gluconic acid, n-acetylalanine, proline, and sulfotyrosine were higher, while the concentrations of 4-methyl-2-oxovaleric acid, 3-methyl-2-oxovaleric acid, and tryptophan were lower in participants with severe sarcopenia than in healthy controls (all, p &amp;lt; 0.05). Of the 57 metabolites quantified in target metabolites, L-alanine (area under the receiver operating characteristic curve [AUC] = 0.760, p = 0.049), gluconic acid (AUC = 0.800, p = 0.023), proline (AUC = 0.785, p = 0.031), and tryptophan (AUC = 0.800, p = 0.023) predicted the presence of severe sarcopenia. In conclusion, plasma metabolomic analysis demonstrated significant changes in amino acid, arginine, proline, and pentose phosphate metabolism in participants with severe sarcopenia. The identified metabolites could be helpful in understanding the underlying pathophysiology of sarcopenia.

Metabolomic profiles to explore biomarkers of severe sarcopenia in older men: A pilot study.

The pathophysiology of sarcopenia is complex and multifactorial; however, it has not yet been fully elucidated. Identifying metabolomic profiles may help clarify the mechanisms underlying sarcopenia. This pilot study explored potential noninvasive biomarkers of severe sarcopenia through metabolomic analysis in community-dwelling older men. Twenty older men (mean age: 81.9±2.8years) were selected from the Korean Frailty and Aging Cohort Study. Participants with severe sarcopenia (n=10) were compared with non-sarcopenic, age- and body mass index-matched controls (n=10). Severe sarcopenia was defined as low muscle mass, low muscle strength, and low physical performance using the Asian Working Group for Sarcopenia 2019 criteria. Non-targeted metabolomic profiling of plasma metabolites was performed using capillary electrophoresis time-of-flight mass spectrometry and absolute quantification was performed in target metabolites. Among 191 plasma metabolic peaks, the concentrations of 10 metabolites significantly differed between severe sarcopenia group and non-sarcopenic controls. The plasma concentrations of L-alanine, homocitrulline, N-acetylserine, gluconic acid, N-acetylalanine, proline, and sulfotyrosine were higher, while those of 4-methyl-2-oxovaleric acid, 3-methyl-2-oxovaleric acid, and tryptophan were lower in participants with severe sarcopenia than in non-sarcopenic controls (all, p<0.05). Among the 53 metabolites quantified as target metabolites, L-alanine (area under the receiver operating characteristic curve [AUC]=0.760; p=0.049), gluconic acid (AUC=0.800; p=0.023), proline (AUC=0.785; p=0.031), and tryptophan (AUC=0.800; p=0.023) determined the presence of severe sarcopenia. Plasma metabolomic analysis demonstrated that L-alanine, gluconic acid, proline, and tryptophan may be potential biomarkers of severe sarcopenia. The identified metabolites can provide new insights into the underlying pathophysiology of severe sarcopenia and serve as the basis for preventive interventions.

Study of Epilobium angustifolium L. amino acids content by HPLC method

The use of plant raw materials is one of the areas of modern pharmaceutical science in the production of herbal drugs. The genus Epilobium counts more than 200 species, many species of which are used in traditional medicine. Among the Epilobium species, Epilobium angustifolium is one of the well-known medicinal plants which have been used worldwide in habitual medicine. There is insufficient information in the literature on the biologically active substances of Epilobium angustifolium L. The presence of three major polyphenol groups: phenolic acids, flavonoids, and ellagitannins were identified in E. angustifolium extracts. Traditionally, the infusion of leaves of this plant could be useful for headaches, cold and gastrointestinal disorder. The Epilobium angustifolium L. as an insufficiently studied plant is a promising object of study, including amino acids composition. To assess the relationship between the production of primary metabolites and their possible therapeutic properties, we analyzed the amino acid profile of the plant Epilobium angustifolium used in traditional medicine. The study of compounds generated by plants as a result of defense mechanisms permits an understanding of the molecular mechanism involved in their medicinal properties.&#x0D; The aim. Thus, the aim of the study was to conduct an HPLC analysis of the amino acids of E. angustifolium to establish the prospects for the use of the raw materials in medical and pharmaceutical practice. The results of the current study will be used in further breeding programs aimed to obtain an industrial form of E. angustifolium suitable for pharmaceutical and food applications.&#x0D; Materials and methods. The determination of amino acids composition of Epilobium angustifolium was conducted using Agilent 1200 (Agilent Technologies, USA).&#x0D; Results. The HPLC method identified sixteen free amino acids and seventeen bound amino acids in the Epilobium angustifolium herb. The studies have shown that Epilobium angustifolium L. herb is mainly composed of free amino acids such as L-phenylalanine (1.65 µg/mg), L-glutamic acid (1.51 µg/mg), L-arginine (1.24 µg/mg), L-alanine (0.98 µg/mg) and L-aspartic acid (0.57 µg/mg), which were presents in the greatest amount. The dominant bound amino acids in the studied raw material were L-glutamic acid, L-aspartic acid, L-leucine, and L-alanine, the content of which was 32.37 µg/mg, 10.59 µg/mg, 8.70 µg/mg, and 6.22 µg/mg respectively.&#x0D; Conclusions. Using the HPLC method determined the amino acids in the herb of Epilobium angustifolium L. The concentrations of L-aspartic acid, L-glutamic acid, L-arginine, L-alanine and L-phenylalanine are predominate among free and bound amino acids in the Epilobium angustifolium L. herb. The result shows that Epilobium angustifolium L. is the source of amino acids, so the use of this plant raw material for new remedies is possible in the future

Comprehensive study of -Alanine passivated colloidal gold nanoparticles and GNP-PVP thin films: Linear optical properties and very large nonlinear refractive index, absorption coefficient, third-order nonlinear susceptibility measurements and effect of passivation

We synthesized gold nanoparticles (GNPs) stabilized in various concentration of l-alanine by chemical reduction method. We measured NLO responses of GNPs when they are dispersed in the l-alanine stabilizer with 1, 2.5 and 5 mM concentrations and when they are implanted into the PVP matix, by using single beam Z- Scan technique with 632 nm He–Ne CW laser for excitation. GNPs exhibited blue shift in localised surface plasmon resonance (LSPR) peak with the l-alanine concentration. The fcc structured GNPs of reducing size with the stabilizer concentration were obtained and characterized by the TEM as well as XRD. The FTIR spectral investigation revealed the formation of strong bond between the surface of GNPs and the l-alanine functional groups and established that l-alanine is very good candidate for stabilization of MNPs. It was observed that these samples show very large nonlinear refractive index, absorption coefficient and third-order nonlinear susceptibility in the order of 10−8cm2W−1, 10−6 cmW−1 and 10−9esu respectively for colloidal suspension of GNPs, and for the GNP-PVP thin films these parameter values were found in the order of 10−6cm2W−1, 10−5cmW−1and 10−6esu respectively. The thermally stimulated, l-alanine concentration dependant, very large NLO responses attributed to the local field effect from Mie resonance and thermal lensing effect originated from thermo-optic phenomenon. The obtained results validate the influence of the stabilizer (l-alanine) on NLO properties.

Studies of solute–solvent interactions of imidazolium-based ionic liquid in water and aqueous l-alanine solution via volumetric and compressibility properties at T = (293.15–313.15) K

The assessment of stability and behavior of ionic liquid is possible through the study of molecular interactions of the ionic liquid in water and mixed aqueous l-alanine solutions. We have studied density (ρ) and speed of sound (u) parameters at various temperatures. Derived parameters like apparent molar volume (Vϕ) and apparent molar isentropic compressibility (KS,ϕ) of solutes are calculated in the temperature range of 293.15 K–313.15 K. For aqueous binary and ternary solutions having ionic liquid [EMIm][MeSO4] and l-alanine as solute components. For ternary aqueous solutions concentration of l-alanine was kept constant (0.05 mol.kg−1). The limiting apparent molar volume (Vϕ0) and compressibility (KS,ϕ0) values for IL are estimated by using smooth extrapolation of Vϕ and KS,ϕ data. In both binary and ternary systems, the limiting apparent molar expansivity (Eϕ0) of solute and coefficient of thermal expansion (α*) and hydration number (nh) parameters have been calculated. The estimation of transfer parameters i.e., transfer volume and transfer compressibility results for transfer of IL from aqueous to aqueous l-alanine solutions are explained in terms of ion–solvent and hydrophobic interaction effects.

Study on the effect of L-Alanine concentration as capping agent on size, structural quality and morphology of KTiOPO4 nanoparticles synthesized by Co-precipitation method

Study on the effect of L-Alanine concentration as capping agent on size, structural quality and morphology of KTiOPO4 nanoparticles synthesized by Co-precipitation method

L-Alanine Prototrophic Suppressors Emerge from L-Alanine Auxotroph through Stress-Induced Mutagenesis in Escherichia coli.

In Escherichia coli, L-alanine is synthesized by three isozymes: YfbQ, YfdZ, and AvtA. When an E. coli L-alanine auxotrophic isogenic mutant lacking the three isozymes was grown on L-alanine-deficient minimal agar medium, L-alanine prototrophic mutants emerged considerably more frequently than by spontaneous mutation; the emergence frequency increased over time, and, in an L-alanine-supplemented minimal medium, correlated inversely with L-alanine concentration, indicating that the mutants were derived through stress-induced mutagenesis. Whole-genome analysis of 40 independent L-alanine prototrophic mutants identified 16 and 18 clones harboring point mutation(s) in pyruvate dehydrogenase complex and phosphotransacetylase-acetate kinase pathway, which respectively produce acetyl coenzyme A and acetate from pyruvate. When two point mutations identified in L-alanine prototrophic mutants, in pta (D656A) and aceE (G147D), were individually introduced into the original L-alanine auxotroph, the isogenic mutants exhibited almost identical growth recovery as the respective cognate mutants. Each original- and isogenic-clone pair carrying the pta or aceE mutation showed extremely low phosphotransacetylase or pyruvate dehydrogenase activity, respectively. Lastly, extracellularly-added pyruvate, which dose-dependently supported L-alanine auxotroph growth, relieved the L-alanine starvation stress, preventing the emergence of L-alanine prototrophic mutants. Thus, L-alanine starvation-provoked stress-induced mutagenesis in the L-alanine auxotroph could lead to intracellular pyruvate increase, which eventually induces L-alanine prototrophy.

Interactions of Bacillus subtilis Basement Spore Coat Layer Proteins.

Bacillus subtilis endospores are exceptionally resistant cells encircled by two protective layers: a petidoglycan layer, termed the cortex, and the spore coat, a proteinaceous layer. The formation of both structures depends upon the proper assembly of a basement coat layer, which is composed of two proteins, SpoIVA and SpoVM. The present work examines the interactions of SpoIVA and SpoVM with coat proteins recruited to the spore surface during the early stages of coat assembly. We showed that the alanine racemase YncD associates with two morphogenetic proteins, SpoIVA and CotE. Mutant spores lacking the yncD gene were less resistant against wet heat and germinated to a greater extent than wild-type spores in the presence of micromolar concentrations of l-alanine. In seeking a link between the coat and cortex formation, we investigated the interactions between SpoVM and SpoIVA and the proteins essential for cortex synthesis and found that SpoVM interacts with a penicillin-binding protein, SpoVD, and we also demonstrated that SpoVM is crucial for the proper localization of SpoVD. This study shows that direct contacts between coat morphogenetic proteins with a complex of cortex-synthesizing proteins could be one of the tools by which bacteria couple cortex and coat formation.

Food forensics on gelatine source via ultra-high-performance liquid chromatography diode-array detector and principal component analysis

This study provided a step-by-step procedure to investigate the distribution of 17 amino acids (AAs) in 50 fish, 50 bovine and 54 porcine gelatines using Ultra-High-Performance Liquid Chromatography Diode-Array Detector (UHPLC–DAD) with the incorporation of principal component analysis (PCA). Dataset pre-processing step, including outlier removal, analysis of variance (ANOVA), dataset adequacy test, dataset transformation and correlation test was performed before the PCA. The method rendered linearity range of 37.5–1000 pmol/µL and accuracy of 85–111% recovery. The bovine and porcine gelatines showed a similar ranking while the l-Alanine (Ala), l-Arginine (Arg) and l-Glutamic acid (Glu) concentrations had differed the fish gelatine from the bovine and porcine gelatines. The PCA, which explained 77.013% cumulative variability at eigenvalue of 5.436, showed AAs with strong FL in PC1 had polar and nonpolar side chains while AAs with strong FL in PC2 had polar side chain. The AAs with moderate and weak FL in PC1 had a nonpolar side chain. The AAs with strong FL of in PC1 were also the same AAs with 7, 6 and 5 strong CMs as determined in the correlation test. The second PCA showed that the l-Serine (Ser), Arg, Glycine (Gly), l-Threonine (Thr), l-Methionine (Met), l-Histidine (His) and L-Hydroxyproline (Hyp) were significant in fish gelatine; Hyp, Met, Thr, Ser, His, Gly, and Arg in bovine gelatine; and l-Proline (Pro), l-Tyrosine (Tyr), l-Valine (Val), l-Leucine (Leu), and l-Phenylalanine (Phe) in porcine gelatine. The 100% fish, bovine and porcine gelatines accommodated grouping 1, 2 and 3, respectively, which proved that AAs with strong FL (Hyp, His, Ser, Arg, Gly, Thr, Pro, Tyr, Met, Val, Leu and Phe) were the significant AAs and becomes the biomarkers to identify the gelatine source. From this study, the PCA was a useful tool to analyse a multivariate dataset that could provide an in-depth understanding of AA distributions as compared to ANOVA and correlation test.

Genomic Heritability and Genome-Wide Association Studies of Plasma Metabolites in Crossbred Beef Cattle.

Metabolites, substrates or products of metabolic processes, are involved in many biological functions, such as energy metabolism, signaling, stimulatory and inhibitory effects on enzymes and immunological defense. Metabolomic phenotypes are influenced by combination of genetic and environmental effects allowing for metabolome-genome-wide association studies (mGWAS) as a powerful tool to investigate the relationship between these phenotypes and genetic variants. The objectives of this study were to estimate genomic heritability and perform mGWAS and in silico functional enrichment analyses for a set of plasma metabolites in Canadian crossbred beef cattle. Thirty-three plasma metabolites and 45,266 single nucleotide polymorphisms (SNPs) were available for 475 animals. Genomic heritability for all metabolites was estimated using genomic best linear unbiased prediction (GBLUP) including genomic breed composition as covariates in the model. A single-step GBLUP implemented in BLUPF90 programs was used to determine SNP P values and the proportion of genetic variance explained by SNP windows containing 10 consecutive SNPs. The top 10 SNP windows that explained the largest genetic variation for each metabolite were identified and mapped to detect corresponding candidate genes. Functional enrichment analyses were performed on metabolites and their candidate genes using the Ingenuity Pathway Analysis software. Eleven metabolites showed low to moderate heritability that ranged from 0.09 ± 0.15 to 0.36 ± 0.15, while heritability estimates for 22 metabolites were zero or negligible. This result indicates that while variations in 11 metabolites were due to genetic variants, the majority are largely influenced by environment. Three significant SNP associations were detected for betaine (rs109862186), L-alanine (rs81117935), and L-lactic acid (rs42009425) based on Bonferroni correction for multiple testing (family wise error rate <0.05). The SNP rs81117935 was found to be located within the Catenin Alpha 2 gene (CTNNA2) showing a possible association with the regulation of L-alanine concentration. Other candidate genes were identified based on additive genetic variance explained by SNP windows of 10 consecutive SNPs. The observed heritability estimates and the candidate genes and networks identified in this study will serve as baseline information for research into the utilization of plasma metabolites for genetic improvement of crossbred beef cattle.

Ergogenic Effect of BCAAs and L-Alanine Supplementation: Proof-of-Concept Study in a Murine Model of Physiological Exercise.

Background: Branched-chain amino acids (BCAAs: leucine, isoleucine, valine) account for 35% of skeletal muscle essential amino acids (AAs). As such, they must be provided in the diet to support peptide synthesis and inhibit protein breakdown. Although substantial evidence has been collected about the potential usefulness of BCAAs in supporting muscle function and structure, dietary supplements containing BCAAs alone may not be effective in controlling muscle protein turnover, due to the rate-limiting bioavailability of other AAs involved in BCAAs metabolism. Methods: We aimed to evaluate the in vivo/ex vivo effects of a 4-week treatment with an oral formulation containing BCAAs alone (2:1:1) on muscle function, structure, and metabolism in a murine model of physiological exercise, which was compared to three modified formulations combining BCAAs with increasing concentrations of L-Alanine (ALA), an AA controlling BCAAs catabolism. Results: A preliminary pharmacokinetic study confirmed the ability of ALA to boost up BCAAs bioavailability. After 4 weeks, mix 2 (BCAAs + 2ALA) had the best protective effect on mice force and fatigability, as well as on muscle morphology and metabolic indices. Conclusion: Our study corroborates the use of BCAAs + ALA to support muscle health during physiological exercise, underlining how the relative BCAAs/ALA ratio is important to control BCAAs distribution.

Glycine Protects Muscle Cells From Wasting in vitro via mTORC1 Signaling.

Glycine supplementation can protect skeletal muscles of mice from cancer-induced wasting, but the mechanisms underlying this protection are not well-understood. The aim of this study was to determine whether exogenous glycine directly protects skeletal muscle cells from wasting. C2C12 muscle cells were exposed to non-inflammatory catabolic stimuli via two models: serum withdrawal (SF) for 48 h; or incubation in HEPES buffered saline (HBS) for up to 5 h. Cells were supplemented with glycine or equimolar concentrations of L-alanine. SF- and HBS-treated myotubes (with or without L-alanine) were ~20% and ~30% smaller than control myotubes. Glycine-treated myotubes were up to 20% larger (P < 0.01) compared to cells treated with L-alanine in both models of muscle cell atrophy. The mTORC1 inhibitor rapamycin prevented the glycine-stimulated protection of myotube diameter, and glycine-stimulated S6 phosphorylation, suggesting that mTORC1 signaling may be necessary for glycine's protective effects in vitro. Increasing glycine availability may be beneficial for muscle wasting conditions associated with inadequate nutrient intake.

Molecular Dynamics Study of the Effect of l-Alanine Chiral Dopants on Diluted Chromonic Solutions.

Atomistic molecular dynamics simulations have been performed for disodium cromoglycate (DSCG) chromonic solutions mixed with l-alanine chiral dopants. We study the fundamental molecular mechanisms induced by low concentrations of l-alanine on diluted DSCG solutions, including their effect on the chromonic aggregates, the solvent, and sodium counterions. Simulations reveal that l-alanine molecules primarily interact with DSCG stacks establishing salt bridges between their respective ammonium and carboxylate groups. Our results demonstrate that l-alanine and sodium counterions jointly establish an intricate network of noncovalent interactions around DSCG aggregates that decreases the global electrostatic repulsion of the chromonic system. Two possible structural effects in DSCG aggregates arise from this electronic stabilization: the increment of the total number of consecutively stacked aromatic planes per DSCG aggregate (intracolumnar effect) or the partial separation reduction between neighboring DSCG columnar sections due to the simultaneous bridging of intercolumnar DSCG carboxylate sites by sodium counterions, forming sodium bridges (intercolumnar effect). Sodium bridges may be responsible for the formation of stacking faults in DSCG aggregates in the form of lateral overlap junctions. This mechanism would explain the difference between lower X-ray correlation lengths with the expected persistence length in chromonics.

Relaxation dynamics of l-alanine in water medium investigated by dielectric relaxation spectroscopy.

The complex dielectric permittivity of L-alanine in aqueous medium at different concentrations and different temperatures were measured in the microwave (0.02 < ν/GHz < 20) frequency region by using open-ended coaxial probe technique. From the reflection coefficient and impedance data, the real and imaginary part of the dielectric permittivity values is determined. It is observed that there is a decrease in the real part of the dielectric permittivity up to certain frequency and an increase in the imaginary part of the dielectric permittivity with increase in the molar concentration of L-alanine in water medium. Based on the experimental data the average relaxation time values are calculated and its behavior is analyzed in terms of bound water and free water molecules. The theoretical dipole moment of L-alanine is calculated at gaseous state as well as in aqueous medium by using PCM and IEFPCM model at HF, DFT/B3LYP and MP2 calculations using 6-311G* basis set. Analysis between experimentally determined parameters and computed dipole moments were discussed. The mean molecular polarizability is calculated from the Lippincott δ function potential model and compared with the Le Fèvre method of polarizability values.

Impact of increasing concentration of l-alanine environment on structural, UV–vis, SHG efficiency, luminescence and dielectric traits of zinc thiourea chloride (ZTC) crystal

The current investigation is aimed to explore the enhancing effect of increasing concentration of amino acid L-alanine (LA) on decisive optical traits of zinc thiourea chloride (ZTC) crystal. The most commercial slow solvent evaporation technique has been adapted to grow pure and LA influenced ZTC crystals at room temperature. The powder X-ray diffraction analysis has been carried out to determine the crystallographic data and analyze the crystalline phase and purity of pure and LA influenced ZTC crystals. The constituent elements of grown crystals have been evaluated by means of energy dispersive spectroscopic technique. The influence of LA on optical transparency of ZTC crystal in range of 190–1000 nm has been ascertained by means of UV-visible spectral analysis. The optical band gap of grown crystals has been evaluated using the transmittance data to discuss the technological impetus of grown crystals for optical devices. The Kurtz-Perry test has been performed to determine the positive impact of organic ligand of LA on second harmonic generation (SHG) efficiency of ZTC crystals. The SHG efficiency of LA influenced ZTC crystal is found to be remarkably higher than pure ZTC and potassium dihydrogen phosphate crystal materials. The effect of LA on photoluminescence nature of ZTC crystal has been investigated in the range of visible region. The impact of LA on temperature dependent dielectric response of ZTC crystal has been investigated within the range of 30–90 °C.

L-Alanine induced thermally stable self-healing guar gum hydrogel as potential drug vehicle for sustained release of hydrophilic drug

A simple approach for preparing self-healable guar gum-graft-acrylic acid (GG-PAA) hydrogel using l-alanine as a cross-linking agent was introduced for the first time. It drastically modifies the mechanical strength of the hydrogel to G′ = 90,570 Pa. Thus, a series of guar gum (GG) based hydrogel was synthesized by varying the concentration of l-alanine from 0.4 to 1% w/v. The hydrogel was characterized by different analytical techniques such as FTIR, HRSEM etc. The mechanical strength of the hydrogel was investigated by rheology analysis and it was observed in terms of storage and loss modulus i.e. G′ & G′′, respectively. Maximum G′ & G′′ (90,560 Pa & 60,820 Pa) were observed when 1 wt% of l-alanine was used as a cross-linking agent. This GG based hydrogel have shown excellent swelling i.e. up to 3350%, which indicates its porous network. The synthesized hydrogel has been identified as a controlled drug delivery gel, which releases 98% of the highly water-soluble loaded drug in 140 h.