Host egg kairomones essential for egg-larval parasitoid,Ascogaster reticulatus Watanabe (Hymenoptera: Braconidae)

Several components of an internal kairomone were identified inside eggs of the host,Adoxophyes sp. (Lepidoptere: Tortricidae), that releases egg deposition of the egg-larval parasitoid,Ascogaster reticulatus Watanabe (Hymenoptera: Braconidae). Pupal hemolymph with the same activity as an internal host egg kairomone was used as a convenient test sample. Heat-treated pupal hemolymph was chromatographed on a Sephadex G-25 column. Each fraction was bioassayed and reacted with ninhydrin. The active fractions were ninhydrin-positive. Each fraction was placed onto an araino acid analyzer, which showed that the amino acids were most abundant in active fractions. Among 22 amino acids, alanine, arginine, glycine, histidine, isoleucine, leucine, methionine, proline, serine, tryptophan, and valine were active. The mixture of these active amino acids was as active as the egg-mass homogenate at the same ratio and concentration, suggesting that the most important component as the kairomone in a host egg is the mixture of several amino acids.     

配位作用毛细管电泳分离天冬中氨基酸

基于配位相互作用的毛细管电泳技术,利用Cu2＋与氨基酸的配位作用,形成具有不同离子淌度的络合物,在50 mmol/L的CuSO4缓冲液中可实现中药天冬中氨基酸的有效分离。在最优条件下,被分离的氨基酸分别为：赖氨酸、组氨酸、精氨酸、甘氨酸、色氨酸、亮氨酸、缬氨酸、谷氨酸。该法无需样品衍生处理,快速、简便,灵敏度较高,值得推广。     

CO2 absorption kinetics and equilibrium solubility measurements in potassium salts of renewable amino acids from plant- and animal-protein

Aqueous solutions containing alkaline salts of natural amino acids, such as those from protein in plant seeds or high protein animal-based waste, are green CO₂-separation solvents. In the present work, potassium salts of nine such amino acids were chosen for an in-depth study: alanine, arginine, aspartic acid, glutamic acid, glycine, leucine, proline, serine, and valine. The kinetics of CO₂ absorption in aqueous solutions of these salts was studied using a stirred cell. From the measurements of the absorption rate at different salt concentrations (molarity 0.1 and higher), CO₂ partial pressures (5–25 kPa), and temperatures (298–308 K), values of the reaction order, rate constant, and activation energy were determined. Additionally, the liquid-side mass transfer coefficient (0.005 cm/s) was also found. Potassium salts of proline, glycine, and arginine were most reactive and, hence, were chosen for equilibrium study. The loading capacity of these salts was measured at 308 K in a vapour–liquid equilibrium setup at near-ambient pressure. On the contrary, the other chosen acids were comparatively less reactive with CO₂.     

Effects of Different Short-Term UV-B Radiation Intensities on Metabolic Characteristics of Porphyra haitanensis

The effects of ultraviolet (UV) radiation, particularly UV-B on algae, have become an important issue as human-caused depletion of the protecting ozone layer has been reported. In this study, the effects of different short-term UV-B radiation on the growth, physiology, and metabolism of Porphyra haitanensis were examined. The growth of P. haitanensis decreased, and the bleaching phenomenon occurred in the thalli. The contents of total amino acids, soluble sugar, total protein, and mycosporine-like amino acids (MAAs) increased under different UV-B radiation intensities. The metabolic profiles of P. haitanensis differed between the control and UV-B radiation-treated groups. Most of the differential metabolites in P. haitanensis were significantly upregulated under UV-B exposure. Short-term enhanced UV-B irradiation significantly affected amino acid metabolism, carbohydrate metabolism, glutathione metabolism, and phenylpropane biosynthesis. The contents of phenylalanine, tyrosine, threonine, and serine were increased, suggesting that amino acid metabolism can promote the synthesis of UV-absorbing substances (such as phenols and MAAs) by providing precursor substances. The contents of sucrose, D-glucose-6-phosphate, and beta-D-fructose-6-phosphate were increased, suggesting that carbohydrate metabolism contributes to maintain energy supply for metabolic activity in response to UV-B exposure. Meanwhile, dehydroascorbic acid (DHA) was also significantly upregulated, denoting effective activation of the antioxidant system. To some extent, these results provide metabolic insights into the adaptive response mechanism of P. haitanensis to short-term enhanced UV-B radiation.     

Metabolomic Profiling of End-Stage Heart Failure Secondary to Chronic Chagas Cardiomyopathy

Chronic Chagas cardiomyopathy (CCC) is the most frequent and severe clinical form of chronic Chagas disease, representing one of the leading causes of morbidity and mortality in Latin America, and a growing global public health problem. There is currently no approved treatment for CCC; however, omics technologies have enabled significant progress to be made in the search for new therapeutic targets. The metabolic alterations associated with pathogenic mechanisms of CCC and their relationship to cellular and immunopathogenic processes in cardiac tissue remain largely unknown. This exploratory study aimed to evaluate the potential underlying pathogenic mechanisms in the failing myocardium of patients with end-stage heart failure (ESHF) secondary to CCC by applying an untargeted metabolomic profiling approach. Cardiac tissue samples from the left ventricle of patients with ESHF of CCC etiology (n = 7) and healthy donors (n = 7) were analyzed using liquid chromatography-mass spectrometry. Metabolite profiles showed altered branched-chain amino acid and acylcarnitine levels, decreased fatty acid uptake and oxidation, increased activity of the pentose phosphate pathway, dysregulation of the TCA cycle, and alterations in critical cellular antioxidant systems. These findings suggest processes of energy deficit, alterations in substrate availability, and enhanced production of reactive oxygen species in the affected myocardium. This profile potentially contributes to the development and maintenance of a chronic inflammatory state that leads to progression and severity of CCC. Further studies involving larger sample sizes and comparisons with heart failure patients without CCC are needed to validate these results, opening an avenue to investigate new therapeutic approaches for the treatment and prevention of progression of this unique and severe cardiomyopathy.     

A Label-Free Cellular Proteomics Approach to Decipher the Antifungal Action of DiMIQ,a Potent Indolo[2,3-b]Quinoline Agent,against Candida albicans Biofilms

Candida albicans forms extremely drug-resistant biofilms, which present a serious threat to public health globally. Biofilm-based infections are difficult to treat due to the lack of efficient antifungal therapeutics, resulting in an urgent demand for the development of novel antibiofilm strategies. In this study, the antibiofilm activity of DiMIQ (5,11-dimethyl-5H-indolo[2,3-b]quinoline) was evaluated against C. albicans biofilms. DiMIQ is a synthetic derivative of indoquinoline alkaloid neocryptolepine isolated from a medicinal African plant, Cryptolepis sanguinolenta. Antifungal activity of DiMIQ was determined using the XTT assay, followed by cell wall and extracellular matrix profiling and cellular proteomes. Here, we demonstrated that DiMIQ inhibited C. albicans biofilm formation and altered fungal cell walls and the extracellular matrix. Cellular proteomics revealed inhibitory action against numerous translation-involved ribosomal proteins, enzymes involved in general energy producing processes and select amino acid metabolic pathways including alanine, aspartate, glutamate, valine, leucine and isoleucine. DiMIQ also stimulated pathways of cellular oxidation, metabolism of carbohydrates, amino acids (glycine, serine, threonine, arginine, phenylalanine, tyrosine, tryptophan) and nucleic acids (aminoacyl-tRNA biosynthesis, RNA transport, nucleotide metabolism). Our findings suggest that DiMIQ inhibits C. albicans biofilms by arresting translation and multidirectional pathway reshaping of cellular metabolism. Overall, this agent may provide a potent alternative to treating biofilm-associated Candida infections.     

Gelation of graphene oxides induced by different types of amino acids

We have investigated gelation of graphene oxide (GO) sheets induced by amino acids. For gelation of single layer GO sheets, six different types of amino acids were added to GO suspension as gelators. To understand gelation mechanism, we varied the concentration and type of amino acids as well as the pH of suspension, and monitored the morphology and rheological properties of reaction mixtures. Gelation was observed in acidic pH only with three types of amino acids (arginine, tryptophan, and cysteine) whereas no gel was formed at other pH values (neutral and basic). As the type of amino acid was varied, both the binding strength between amino acid and GO and the moduli (G′ and G′′) of reaction mixtures followed the same order, arginine > cysteine > tryptophan > asparagine > aspartic acid > glycine. To rationalize these results, we considered interactions between amino acid side chains and GO sheets (i.e., electrostatic interaction, π–π stacking, and hydrogen bonding), and found that the hydrogel formed by electrostatic attraction with arginine exhibited shorter gel time and larger moduli than the other samples. Finally, synthesis of GO hydrogel at physiological pH was demonstrated by increasing the concentration of GO sheets.     

Antioxidant efficacy of amino acids in methyl linoleate at different relative humidities

Antioxidant efficacy of the amino acids methionine, tryptophan, aspartic acid, serine, alanine and arginine in methyl linoleate were compared to a methyl linoleate control at 2,50 or 79% relative humidity (RH) at 37°C. Antioxidant efficacy varied with RH and the individual amino acids. Arginine had the highest antioxidant efficacy at all RH values compared to the control. The efficacy of alanine was equal to that of arginine at RHs of 50 and 79% but was lower at 2% RH. The presence of aliphatic, alkaline amino, hydroxyl or thiol groups in the side chain of the amino acids increased the antioxidant efficacy at high RHs.     

Theoretical Studies of Cyanophycin Dipeptides as Inhibitors of Tyrosinases

The three-dimensional structure of tyrosinase has been crystallized from many species but not from Homo sapiens. Tyrosinase is a key enzyme in melanin biosynthesis, being an important target for melanoma and skin-whitening cosmetics. Several studies employed the structure of tyrosinase from Agaricus bisporus as a model enzyme. Recently, 98% of human genome proteins were elucidated by AlphaFold. Herein, the AlphaFold structure of human tyrosinase and the previous model were compared. Moreover, tyrosinase-related proteins 1 and 2 were included, along with inhibition studies employing kojic and cinnamic acids. Peptides are widely studied for their inhibitory activity of skin-related enzymes. Cyanophycin is an amino acid polymer produced by cyanobacteria and is built of aspartic acid and arginine; arginine can be also replaced by other amino acids. A new set of cyanophycin-derived dipeptides was evaluated as potential inhibitors. Aspartate–glutamate showed the strongest interaction and was chosen as a leading compound for future studies.     

Antioxidative characteristics of oils in ground pork-fat patties cooked with soy sauce

Ground pork-fat patties were cooked alone (control), with NaCl solution, with NaCl solution containing sucrose, with fermented soybean broth, with fermented black soybean broth, and with commercial soy sauce products at 125°C for 2 h. The top-layer oils were then stored at 60°C for periodical determinations of conjugated diene hydroperoxide (CDHP) contents. The fermented broth-cooked and soy sauce-cooked oils were stable against CDHP formation during storage. This supports the customary impression that soy sauce-cooked pork is stable against oxidative rancidity. Analysis of the fatty acid compositions showed the presence of linoleic, linolenic, and arachidonic acids, which are susceptible to oxidation. When the fermented brothcooked oils were extracted with methanol, concentrated, and introduced to the control oils for storage, an estimated antioxidative potency close to that of 2 ppm butylated hydroxyanisole was observed. In comparing free amino acid compositions of the fermented soybean and black soybean broths before and after cooking the ground pork-fat patties, threonine, serine, glutamic acid, alanine, isoleucine, leucine, tryptophan, and tyrosine contents tecreased while proline, valine, histidine, and arginine contents increased.     

Modeling of aqueous amino acid and polypeptide solutions with PC-SAFT

Vapor pressures, liquid densities and solubilities of aqueous amino acid and oligopeptide solutions were modeled with an equation of state based on PC-SAFT. The amino acids glycine (Gly), alanine (Ala), serine (Ser), proline (Pro), and valine (Val) as well as the oligopeptides (Gly)_n=1−5, and Ala(Gly)_n=1−4 were considered. Five pure-component model parameters for each amino acid were fitted using experimental densities, vapor pressures, and solubility data. The oligopeptides were treated as co-polymers built up by the respective amino acids. Thus, no additional parameters had to be fitted for the prediction of densities and vapor–liquid behavior of their aqueous solutions besides the segment number. The model is able to excellently reproduce the experimental densities, vapor pressures and solubility data of aqueous amino acid and oligopeptide solutions.     

Stabilization of a monoclonal antibody during purification and formulation by addition of basic amino acid excipients

BACKGROUND: Protein stability of therapeutic monoclonal antibodies during processing and final storage is imperative for the commercial success of the product. Amino acid addition is one of the options for stabilization of proteins that can be employed during the manufacturing process and storage. RESULTS: Use of arginine in the elution buffer during Protein A purification and subsequent neutralization doubled the yield of antibody compared with the original glycine‐based elution buffer. The role of amino acids in stabilizing monoclonal antibody liquid formulations was then studied using differential scanning calorimetry. Increase in the unfolding transition temperatures (T_m) of immunoglobulin G (IgG) was measured after supplementing a glycine buffer with a range of amino acids. The basic amino acids histidine, lysine, and arginine stabilized all three domains of IgG. The neutral amino acids serine and alanine provided less stabilization; glutamine, proline, and the acidic amino acids provided negligible stabilization. CONCLUSION: The positive charge on the side‐chain of histidine, lysine, and arginine appears to be the most important factor affecting the IgG stabilization. It is probable that the mechanism for IgG stabilisation is the same for all of the basic amino acids and that it binds transiently to IgG side chains, altering water populations in the solvation shell, making unfolding and aggregation less energetically favourable. Copyright © 2011 Society of Chemical Industry     

High-resolution crystal structure of M-protease: phylogeny aided analysis of the high-alkaline adaptation mechanism

M-protease is a subtilisin-family serine protease produced by an alkaliphilic Bacillus sp. strain. Optimal enzymatic activity of the protein occurs at pH 12.3. The crystal structure of M-protease (space group P2(1)2(1)2(1), a = 62.3, b = 75.5, c = 47.2 A) has been refined to a crystallographic R-factor of 17.2% at 1.5 A resolution. The alkaline adaptation mechanism of the enzyme was analyzed. Molecular phylogeny construction was used to determine the amino acid substitutions that occurred during the high-alkaline adaptation process. This analysis revealed a decrease in the number of negatively charged amino acids (aspartic acid and glutamic acid) and lysine residues and an increase in arginine and neutral hydrophilic amino acids (histidine, asparagine and glutamine) residues during the course of adaptation. These substitutions increased the isoelectric point of M- protease. Some of the acquired arginine residues form hydrogen bonds or ion pairs to combine both N- and C-terminal regions of M-protease. The substituted residues are localized to a hemisphere of the globular protein molecule where positional shifts of peptide segments, relative to those of the less alkaliphilic subtilisin Carlsberg, are observed. The biased distribution and interactions caused by the substituted residues seem to be responsible for stabilization of the conformation in a high-alkaline condition.      

Lipids of human myocardium

The major lipid classes, including some phospholipids, and their fatty acid profiles have been measured in portions of left ventricular muscle and psoas muscle obtained at autopsy. Atrial appendages and ventricular muscle removed during cardiac surgery were examined also. The proportions of the individual phospholipids were the same in all the muscles, having an excess of phosphatidyl ethanolamine and phosphatidyl serine compared with the serum. Their fatty acid profiles resembled those obtained from other locations. The triglyceride content of the myocardium was relatively constant (except in the atrial appendage) but did rise slightly with increasing obesity. The free fatty acid concentration in the myocardium was relatively high and had a variable fatty acid profile.     

The activity coefficients of glycine,DL‐Serine and DL‐Valine in aqueous solutions containing nitrates at 298.15 K

An electrochemical method was used to measure the mean activity coefficients of amino acids in water‐electrolyte‐amino acid systems. The amino acids were glycine, DL‐serine and DL‐valine and the electrolytes were KNO₃ and NaNO₃. The activity coefficients of the electrolytes were obtained from the e.m.f measurements in an electrochemical cell with an anion and a cation ion‐selective electrodes, each measured versus a double junction reference electrode at 298.15 K. The activity coefficients of the amino acids in the ternary systems were obtained from those of the electrolyte according to the cross differential relation. A simple semi‐empirical model based on a modification of a more complex form, derived from perturbation theory, was used to correlate the activity coefficients in binary aqueous solutions and in ternary systems.     

Some environmental factors affecting free amino acid composition in six varieties of peanuts

This study involved six Spanish type entries (five commercial varieties and a plant introduction) grown in the National Variety Tests in Oklahoma and Georgia under both irrigated and nonirrigated conditions. Significant effects (Georgia vs Oklahoma) were observed on aspartic acid, proline, glycine, valine, isoleucine, peptide, ammonia, and histidine. Significant differences for irrigated vs nonirrigated in the two states for aspartic acid, threonine, proline, glutamic acid, isoleucine, leucine, tyrosine, phenylalanine, peptide, ammonia, and histidine were observed. Significant differences among the six entries were observed for glutamic acid, leucine, tyrosine, phenylalanine, ammonia, histidine, arginine, tryptophan, and total amino acids. None of the treatments produced significant changes in measured amounts of serine, alanine, methionine, and lysine. Significant differences for Georgia vs Oklahoma and irrigated vs nonirrigated for Kjeldahl nitrogen of the whole peanut were noted. Presented at the AOCS Spring Meeting, New Orleans, May 1973. Journal paper 2636 of the Oklahoma Agricultural Experiment Station. ARS, USDA.     

Influence of Prokelisia Planthoppers on Amino Acid Composition and Growth of Spartina alterniflora

The effects of feeding by the planthopper Prokelisia dolus on its hostSpartina alterniflorawere examined under conditions of both high and low plant-nitrogen subsidy. Phloem feeding by P. dolus reduced the concentrations of γ-aminobutyric acid, isoleucine, leucine, lysine, threonine, and valine in S. alterniflora leaves. In contrast, glutamic acid was the only amino acid that increased in plants fed upon by planthoppers, and this increase was only observed in plants in the high N-fertilizer treatment. Planthopper feeding reduced the total concentration of amino/imino acids tested, and the concentration of essential amino acids, although this difference was not quite statistically significant. Generally, concentrations of individual amino acids in Spartina were higher in the high N-fertilizer treatment. Planthopper feeding and nitrogen fertilization also significantly impacted Spartina growth and production. Culm elongation, new leaf production, and tiller elongation were reduced and leaf mortality was increased on plants fed upon by planthoppers. Furthermore, planthoppers showed enhanced survival on the high-N plants. Nitrogen fertilization also moderated the effects of sap feeding on plant growth because the reduction of culm elongation associated with planthopper feeding was more pronounced in the low N-fertilizer treatment. Thus, feeding by P. dolus adversely affected both the nutritional quality and growth of Spartinaeffects that were tempered, in part, in plants receiving high nitrogen subsidy. Our results are discussed in the context of feeding-induced changes in plant quality and quantity as possible mechanisms mediating competitive interactions in Prokelisia planthoppers.     

A Novel UPLC-MS/MS Method Identifies Organ-Specific Dipeptide Profiles

Background: Amino acids have a central role in cell metabolism, and intracellular changes contribute to the pathogenesis of various diseases, while the role and specific organ distribution of dipeptides is largely unknown. Method: We established a sensitive, rapid and reliable UPLC-MS/MS method for quantification of 36 dipeptides. Dipeptide patterns were analyzed in brown and white adipose tissues, brain, eye, heart, kidney, liver, lung, muscle, sciatic nerve, pancreas, spleen and thymus, serum and urine of C57BL/6N wildtype mice and related to the corresponding amino acid profiles. Results: A total of 30 out of the 36 investigated dipeptides were detected with organ-specific distribution patterns. Carnosine and anserine were most abundant in all organs, with the highest concentrations in muscles. In liver, Asp-Gln and Ala-Gln concentrations were high, in the spleen and thymus, Glu-Ser and Gly-Asp. In serum, dipeptide concentrations were several magnitudes lower than in organ tissues. In all organs, dipeptides with C-terminal proline (Gly-Pro and Leu-Pro) were present at higher concentrations than dipeptides with N-terminal proline (Pro-Gly and Pro-Leu). Organ-specific amino acid profiles were related to the dipeptide profile with several amino acid concentrations being related to the isomeric form of the dipeptides. Aspartate, histidine, proline and serine tissue concentrations correlated with dipeptide concentrations, when the amino acids were present at the C- but not at the N-terminus. Conclusion: Our multi-dipeptide quantification approach demonstrates organ-specific dipeptide distribution. This method allows us to understand more about the dipeptide metabolism in disease or in healthy state.     

Anti-Fibrotic Effects of Class I HDAC Inhibitor,Mocetinostat Is Associated with IL-6/Stat3 Signaling in Ischemic Heart Failure

Background: Recent studies have linked histone deacetylases (HDAC) to remodeling of the heart and cardiac fibrosis in heart failure. However, the molecular mechanisms linking chromatin remodeling events with observed anti-fibrotic effects are unknown. Here, we investigated the molecular players involved in anti-fibrotic effects of HDAC inhibition in congestive heart failure (CHF) myocardium and cardiac fibroblasts in vivo. Methods and Results: MI was created by coronary artery occlusion. Class I HDACs were inhibited in three-week post MI rats by intraperitoneal injection of Mocetinostat (20 mg/kg/day) for duration of three weeks. Cardiac function and heart tissue were analyzed at six week post-MI. CD90⁺ cardiac fibroblasts were isolated from ventricles through enzymatic digestion of heart. In vivo treatment of CHF animals with Mocetinostat reduced CHF-dependent up-regulation of HDAC1 and HDAC2 in CHF myocardium, improved cardiac function and decreased scar size and total collagen amount. Moreover, expression of pro-fibrotic markers, collagen-1, fibronectin and Connective Tissue Growth Factor (CTGF) were reduced in the left ventricle (LV) of Mocetinostat-treated CHF hearts. Cardiac fibroblasts isolated from Mocetinostat-treated CHF ventricles showed a decrease in expression of collagen I and III, fibronectin and Timp1. In addition, Mocetinostat attenuated CHF-induced elevation of IL-6 levels in CHF myocardium and cardiac fibroblasts. In parallel, levels of pSTAT3 were reduced via Mocetinostat in CHF myocardium. Conclusions: Anti-fibrotic effects of Mocetinostat in CHF are associated with the IL-6/STAT3 signaling pathway. In addition, our study demonstrates in vivo regulation of cardiac fibroblasts via HDAC inhibition.