Essential Amino Acids Methionine Research Articles

Inhibition of mild steel corrosion in hydrochloric acid medium by polymeric inhibitors containing residues of essential amino acid methionine

Ethyl ester hydrochloride of amino acid l-methionine 1 was converted to cationic monomers N,N-diallyl methionine ethyl ester hydrochloride 2 and hydrochloride salt of N,N-diallylmethionine 3. Cationic monomers 2 and 3 underwent alternate copolymerization with SO2 in dimethyl sulfoxide to give terpolymers 4 and 5, respectively, both having ≈ 1:1 ratio of sulfide and sulfoxide motifs owing to O transfer from dimethyl sulfoxide to the S. The sulfide groups in 5 have been oxidized with H2O2 to give polymer sulfoxide 6. In the presence of a small concentration of 35.2 µM (~ 11 ± 1 ppm) of each of the polymers 4, 5 and 6, the inhibition efficiency against mild steel corrosion in 1.0 M HCl at 60 °C was determined to be 90.8, 98.7 and 93.0%, respectively. The inhibition efficiency obtained from gravimetric weight loss was corroborated by the findings of potentiodynamic polarization and electrochemical impedance spectroscopy methods. Adsorption of polymer compounds onto the mild steel surface followed a mixture of chemisorption and physisorption processes and obeyed Langmuir, Temkin and Freundlich adsorption isotherms. The X-ray photoelectron spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy techniques further confirmed that the synthesized compounds formed a protective film onto the metal surface and prove it against further corrosion attack.

Recent Developments on the Origin and Nature of Reductive Sulfurous Off-Odours in Wine

Reductive sulfurous off-odors are still one of the main reasons for rejecting wines by consumers. In 2008 at the International Wine Challenge in London, approximately 6% of the more than 10,000 wines presented were described as faulty. Twenty-eight percent were described as faulty because they presented “reduced characters” similar to those presented by “cork taint” and in nearly the same portion. Reductive off-odors are caused by low volatile sulfurous compounds. Their origin may be traced back to the metabolism of the microorganisms (yeasts and lactic acid bacteria) involved in the fermentation steps during wine making, often followed by chemical conversions. The main source of volatile sulfur compounds (VSCs) are precursors from the sulfate assimilation pathway (SAP, sometimes named as the “sulfate reduction pathway” SRP), used by yeast to assimilate sulfur from the environment and incorporate it into the essential sulfur-containing amino acids methionine and cysteine. Reductive off-odors became of increasing interest within the last few years, and the method to remove them by treatment with copper (II) salts (sulfate or citrate) is more and more questioned: The effectiveness is doubted, and after prolonged bottle storage, they reappear quite often. Numerous reports within the last few years and an ongoing flood of publications dealing with this matter reflect the importance of this problem. In a recent detailed review, almost all relevant aspects were discussed on a scientific data basis, and a “decision tree” was formulated to support winemakers handling this problem. Since we are dealing with a very complicated matter with a multitude of black spots still remaining, these advices can only be realized using specific equipment and special chemicals, not necessarily found in small wineries. The main problem in dealing with sulfurous compounds arises from the high variability of their reactivities. Sulfur is a metalloid with a large valence span across eight electron transformations from S (−II) up to S (+VI). This allows it to participate in an array of oxidation, reduction and disproportionation reactions, both abiotic and linked to microbial metabolism. In addition, sulfur is the element with the most allotropes and a high tendency to form chains and rings, with different stabilities of defined species and a high interconvertibility among each other. We suppose, there is simply a lack of knowledge of what is transferred during filling into bottles after fermentation and fining procedures. The treatment with copper (II) salts to remove sulfurous off-odors before filling rather increases instead of solving the problem. This paper picks up the abundant knowledge from recent literature and tries to add some aspects and observations, based on the assumption that the formation of polythionates, hitherto not taken into consideration, may explain some of the mystery of the re-appearance of reductive off-odors.

Impacts of dietary amino acid composition and microbial presence on preference and performance of immatureLucilia sericata(Diptera: Calliphoridae)

1. As primary colonisers of ephemeral resources, the common green bottle fly,Lucilia sericata, must exercise efficient resource exploitation strategies to maximise fitness. Foraging incurs costs, so the efficient evaluation of resources is essential for individuals relying on fragmented patches whose dissimilarity may result in fitness consequences for offspring. Thus, selective pressures between carrion‐using insects and carrion‐associated microbes are expected to occur.2. Microbes play a pivotal role in adult fly assessment of resources via production of volatile organic compounds (VOCs) resulting from the breakdown of essential amino acids. If one assumes that chemoreception of these VOCs provides public information regarding the corresponding essential amino acids, the resulting effects on maternal decision‐making could impact larval resource exploitation.3. The essential amino acids phenylalanine, methionine, valine, and tryptophan, the corresponding VOCs of which are known fly attractants, were used to construct imbalanced diets with and without antimicrobial treatment to investigate the impact of suboptimal food sources on larvalL. sericata.4. The results of this study demonstrate that both amino acid composition and microbial presence influence behaviour, with larvae displaying a preference for untreated diets lacking methionine and a complete reversal in preference for antimicrobial‐treated diets. This interaction between diet and antimicrobial treatment indicates that the presence of microbes that produce essential amino acids may impact larval resource utilisation strategies. This investigation into larval performance on diets deficient in amino acids that provide important VOC cues to maternal flies provides a stepping stone for dissecting larval behavioural strategies on ephemeral resources when faced with limited choices.

Abstract LB-247: Targeting methionine metabolism to eradicate cancer stem cells

Abstract Purpose: Rare cells within tumors with stem cell-like properties (cancer stem stem cells or CSCs) play a critical role in treatment resistance and cancer recurrence because CSCs are resistant to chemotherapy. Hence, elimination of CSCs will require new treatment approaches to improve the long-term outcomes for patients with cancer. We have recently discovered that breast CSCs require the essential amino acid methionine for cell survival. Methionine is converted by the enzyme MAT2A to S-adenosylmethionine (SAM), a universal methyl donor that regulates gene expression by DNA and histone methylation. We hypothesize that the methionine dependence of CSCs is a unique metabolic vulnerability that we can target by dietary methionine restriction (MR) and/or inhibiting the enzyme that converts methionine to SAM (MAT2A). Experimental design and Results: We examined the effects of MR and/or MAT2A inhibition on the formation of CSC-enriched “mammospheres” and on the expression of CSC markers (CD44hi/C24low) in triple (ER/PR/HER2)-negative breast cancer (TNBC) cells. MR inhibited mammosphere formation, induced apoptosis and reduced the CD44hi/C24low CSC population. These effects of MR were partly rescued by addition of SAM, suggesting that CSCs are dependent on SAM for cell survival. MR resulted in robust induction of MAT2A mRNA and protein levels. Inhibition of MAT2A with cycloleucine, or by silencing MAT2A with specific siRNAs, reduced mammosphere formation and the CD44hi/C24low CSC population. Strikingly, the effects of cycloleucine or MAT2A silencing on cancer stem cells were dramatically potentiated by MR. Treatment of TNBC mammospheres with MR or cycloleucine suppressed the expression of transcriptional regulators of pluripotency and epithelial-to-mesenchymal transition, while the combination of MR and cycloleucine resulted in more robust reductions in the expression of these transcription factors than either intervention alone. Consistent with these effects, the combination of dietary MR and cycloleucine was more effective than either treatment alone at inhibiting primary tumor growth and lung metastases in a murine TNBC model. Conclusion: Our findings point to previously unrecognized metabolic vulnerability of CSCs, namely, their intrinsic dependence on methionine and SAM for cell survival. MR induces expression of MAT2A, thereby providing an explanation for the robust synergy between MR and MAT2A inhibition/silencing in supressing CSC survival. Moreover, cycloleucine potentiates the activity of dietary MR in a murine metastatic TNBC model, providing proof-of-principle in vivo evidence for this novel metabolic approach to eradicate CSCs and thereby improve long-term clinical outcomes in poor-prognosis TNBC. Citation Format: Elena Strekalova, Dmitry Malin, Dominik Hoelper, Peter Lewis, Vincent Cryns. Targeting methionine metabolism to eradicate cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-247.

Effects of Dietary Acute Tryptophan Depletion (ATD) on NPY Serum Levels in Healthy Adult Humans Whilst Controlling for Methionine Supply-A Pilot Study.

Central nervous serotonin (5-HT) can influence behaviour and neuropsychiatric disorders. Evidence from animal models suggest that lowered levels of neuropeptide Y (NPY) may have similar effects, although it is currently unknown whether decreased central nervous 5-HT impact NPY concentrations. Given that the production of NPY is dependent on the essential amino acid methionine (MET), it is imperative to account for the presence of MET in such investigations. Hence, this study sought to examine the effects of acute tryptophan depletion (ATD; a dietary procedure that temporarily lowers central nervous 5-HT synthesis) on serum concentrations of NPY, whilst using the potential renal acid load indicator (PRAL) to control for levels of MET. In a double-blind repeated measures design, 24 adult humans randomly received an AA-load lacking in TRP (ATD) on one occasion, and a balanced control mixture with TRP (BAL) on a second occasion, both with a PRAL of nearly 47.3 mEq of MET. Blood samples were obtained at 90, 180, and 240 min after each of the AA challenges. ATD, and therefore, diminished substrate availability for brain 5-HT synthesis did not lead to significant changes in serum NPY concentrations over time, compared to BAL, under an acute acidotic stimulus.

Perturbation of Homocysteine Homeostasis Leads to Cellular Epigenetic Modification And Endothelial Injury in Acute Myocardial Infarction

Homocysteine is a highly reactive, sulfur‐containing amino acid formed as a byproduct of the metabolism of the essential amino acid methionine. Homocysteine used to be thought of as a risk factor for atherosclerosis, but emerging data have suggested that S‐adenosylhomocysteine (SAH), an intermediate metabolite of homocysteine, might be a better indicator of vascular diseases. In this study, we investigated the epigenetic role and clinical significance of SAH‐homocysteine homeostasis in acute myocardial infarction. A cell culture system was established to assess the interplay between SAH and homocysteine using human coronary artery endothelial cells (ECs). Homocysteine alone did not affect EC survival up to 500 uM; however, in the presence of adenosine/EHNA, homocysteine (25–500 uM) dose‐dependently increased intracellular SAH and promoted TUNEL‐positive apoptotic cell death. There was a concomitant downregulation of fibroblast growth factor 2 (FGF2), a critical cytokine for EC survival, through extensive DNA methylation at CpG dinucleotides in the FGF2 gene promoter. These pro‐apoptotic effects in ECs were markedly attenuated when adenosine/EHNA was removed from the culture medium. In patients with acute ST‐elevation myocardial infarction (STEMI), the plasma SAH levels quantitated by liquid chromatography coupled to tandem mass spectrometry (LC‐MS/MS) were significantly higher than those in healthy controls. In contrast, the plasma homocysteine concentrations were similar between STEMI and healthy subjects. Moreover, STEMI patients who had an obvious clinical improvement also demonstrated a significant decrease in their plasma SAH levels at subsequent follow‐up. Our data conclude that the perturbation of SAH‐homocysteine homeostasis in ECs leads to cellular epigenetic modification and endothelial injury in acute myocardial infarction. Elevation of plasma SAH but not homocysteine in STEMI patients further supports the notion that SAH is a better indicator of vascular diseases than homocysteine.Support or Funding InformationThis work was supported by grants NSC101‐2320‐B‐002‐026 from the National Science Council and MOST‐106‐2314‐B‐002 ‐156 ‐MY2 (Dr. Po‐Yuan Chang) from the Ministry of Science and Technology, Taipei, Taiwan.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effect of plant growth promoting Bacillus spp. on nutritional properties of Amaranthus hypochondriacus grains

Amaranth (Amaranthus hypochondriacus Linn.) is an important pseudocereal crop having important nutrients along with the indispensable amino-acids. The present study was aimed to study the effect of plant growth promoting bacilli on proximate constituents of amaranth grains, including three of the essential amino acids (methionine, lysine and, tryptophan). The combination of Bacillus pumilus and Bacillus subtilis showed a significant increase in different proximate constituents, including crude protein (22.13%), dry matter (32.25%), fat (30.77%), and carbohydrate (49.08%) in amaranth grains. Similarly, a significant increase in essential amino-acids (methionine 47.68%, lysine 59.41% and, tryptophan 38.05%) was recorded. This study suggests that the combination of Bacillus pumilus BS-27 and Bacillus subtilis BS-58 provides the natural, persistent and durable potential to enhance the nutritive value of the crop. Therefore, present study was designed to explore the enhancement of most desirable amino acid synthesis in amaranth due to application of plant growth promoting Bacillus spp.

Productivity of bumpers for the microelemental correction of their rations

One of the most important factors in the full feeding of animals is the optimal supply of nutrients and biologically active substances, namely, trace elements. Lacking or excessive MI in rations leads to a disturbance of metabolism in the body, inhibits development and growth, reduces productive qualities, and, by reducing immunity, causes various diseases. The final factor is the close interconnection of trace elements with proteins, carbohydrates, fats, which ultimately reflects on the physiological state of a living organism. Soil and climatic conditions of the central region are characterized by a lack of feed and water of the following trace elements: cobalt, copper, iron, manganese, zinc. The bioavailability of these microelements for the animal organism is lower than the physiological norm. Increase of biological availability of trace elements by tissues of an organism can be achieved due to their connection with an organic ligand, and in our case with an essential amino acid methionine, thus creating chelating compounds – metionates. The purpose of the article is to analyze the influence of chelate compounds on the protein metabolism of fattening bulls. The results of hemoglobin studies showed us that its content was also dependent on the applied trace elements. Similarly, an increase in the number of erythrocytes also increased the concentration of hemoglobin. Three months after the application of corrective supplements, the hemoglobin content in the blood of experimental bovine animals in the 2, 3, 4th experimental groups was increased compared to the control group. In addition, a similar picture was observed in the dynamics during the whole experimental period of fattening. The best effect on the hemoglobin content in the blood was shown by the addition of chelates (metionates) in the 4th experimental group, which is also confirmed statistically. The results of the obtained data indicate that the correctional additives of the microelements and their chelates (metionates) used by us increase the level of total protein in the blood serum of fattening bulls. During the trial period, their concentration in the bulls of the control group also increased, but this is due to the age and growth of animals. However, in the Bugites of experimental groups, the content of total protein significantly increased under the influence of corrective supplementation of trace elements, and especially under the influence of their chelate compounds (metionates). Already three months after the micronutrient supplement was fed, the level of total protein in the serum of bulls in all experimental groups significantly increased compared to the animals in the control group.

Reduced HeLa cell viability in methionine‐containing cell culture medium irradiated with microwave‐excited atmospheric‐pressure plasma

The mechanism underlying the death of cancer cells incubated in plasma‐activated medium (PAM) prepared by irradiation of culture medium with atmospheric‐pressure plasma is revealed by analyzing changes in the culture medium composition using liquid chromatography‐tandem mass spectrometry and nuclear magnetic resonance spectroscopy. The concentration of the essential amino acid methionine declined in microwave‐excited plasma‐irradiated medium, whereas, that of methionine sulfoxide increased due to oxidation of methionine. The decrease in methionine concentration in the cell culture medium rather than the increase in methionine sulfoxide leads to the decline in the survival rate of HeLa cells incubated in PAM. These results provide useful insights into the mechanism of selective cancer cell death in PAM.

Understanding a metabolic weakness

Cancer Metabolism Cells use the same precursor to produce the essential amino acids methionine and cysteine. Lien et al. determined why human breast cancer cells with oncogenic mutations in the lipid kinase PI3K cannot produce methionine, a metabolic vulnerability called methionine dependency. Oncogenic PI3K mutants inhibited the expression and activity of xCT, a transporter that imports an oxidized form of cysteine, thereby limiting precursor availability for methionine synthesis. Thus, methionine restriction could potentially be used to treat breast tumors expressing oncogenic PI3K mutants. Sci. Signal. 10 , eaao6604 (2017).

EFFECTS OF DIETARY PROTEIN AND THREONINE LEVELS ON GROWTH PERFORMANCE AND IMMUNOCOMPETENCE IN BROILER CHICKENS

The present work was conducted to study the effects of feeding low crude protein diets (LCP-diets) with supplementation of threonine (Thr) on growth performance and immunocompetence in broiler chickens. One day old 264 Cobb chicks were divided into 6 equal groups (each of 4 replicates and each replicate was of 11 chicks). The 1st group is considered the control one and fed normal basal control starter, grower and finisher diets containing the recommended levels of CP, threonine, methionine, lysine, tryptophan, valine, arginine and metabolizable energy as specified for Cobb500 broiler performance. The 2nd experimental group was fed ideal protein diets which were formulated to contain the minimum nutrient specifications based upon supplementing digestible essential amino acids (lysine, methionine, tryptophan, threonine, arginine, and valine). The other experimental chick groups (3rd, 4th, 5th and 6th groups) were fed isocaloric diets containing low levels of total dietary CP% (1 and 2% less than the minmum recommended CP%) with supplementation of Thr to 120 or 140% of the minimum recommended levels. The diets were isocaloric (3035, 3108 and 3180 Kcal/kg for starter, grower and finisher diets respectively). All chicks were vaccinated against Newcastle disease virus (NDV) at day 14 of age through eye drops. Growth performance indices (body weight, feed intake, feed conversion ratio and protein efficiency ratio) were measured. Blood samples were collected from the broilers at 14, 21, 28 and 35 days of age to determine the serum titre of antibodies against NDV using haemagglutination inhibition test (HI). At 42 days of age, blood samples were collected for determination of serum metabolites and 12 chickens from each group were slaughtered to obtain some of the carcass traits. The results revealed that BW and FCR of the broilers fed 2% LCP- diets with 120 or 140% Thr supplementation were significantly lowered than those fed control or ideal protein diets, as well as those fed 1% LCP- diets with Thr supplementation. There were no differences between the groups in dressed carcass percentages. The abdominal fat % in the carcass of the broiler chickens was not significantly affected by decreasing the dietary CP or supplementation of threonine. Liver weight% significantly increased with feeding the 2% LCP- diets. Feeding 2% LCP- diets also resulted in significant increase in serum uric acid and decreased serum total protein, albumin and globulin. The highest HI titer values and lowest serum levels of uric acid were observed in chickens fed ideal protein diets. While, chickens fed LCP- diets (-2%) had reduced HI titer values. from the present study, it could be concluded that the dietary protein level could be decreased by 1% of the recommended levels with threonine supplementation to 120 % of requirements with no adverse effects on body weight development, FCR, serum metabolites and immune competence in broiler chickens. Formulating broiler diets based upon digestible essential amino acids achieved optimal growth performance and maintained immunocompetence.

Quality Protein Maize Based on Reducing Sulfur in Leaf Cells.

Low levels of the essential amino acids lysine (Lys) and methionine (Met) in a maize-based diet are a major cost to feed and food. Lys deficiency is due to the abundance of Lys-poor proteins in maize kernels. Although a maize mutant, opaque-2 (o2), has sufficient levels of Lys, its soft kernel renders it unfit for storage and transportation. Breeders overcame this problem by selecting quantitative trait loci (QTL) restoring kernel hardness in the presence of o2, a variety called Quality Protein Maize (QPM). Although at least one QTL acts by enhancing the expression of the γ-zein proteins, we could surprisingly achieve rebalancing of the Lys content and a vitreous kernel phenotype by targeting suppression of γ-zeins without the o2 mutant. Reduced levels of γ-zeins were achieved with RNA interference (RNAi). Another transgenic event, PE5 expresses the Escherichia coli enzyme 3'-phosphoadenosine-5'-phosphosulfate reductase involved in sulfate assimilation, specifically in leaves. The stacked transgenic events produce a vitreous endosperm, which has higher Lys level than the classical opaque W64Ao2 variant. Moreover, due to the increased sulfate reduction in the leaf, Met level is elevated in the seed. Such a combination of transgenes produces hybrid seeds superior to classical QPMs that would neither require a costly feed mix nor synthetic Met supplementation, potentially creating a novel and cost-effective means for improving maize nutritional quality.

AMINO ACID AND FATTY ACID COMPOSITION OF ETHIOPIAN TARO

The purpose of this study was designed to investigate the amino acid and fatty acid composition of taro leaf and corm samples. An UHPLC and GC-FID method was used for the determination of amino acids and fatty acid composition, respectively. Taro leaf was processed as a powder and pre-curd concentrates while the corm was pre-gelatinized with and without peel prior to the analysis. The amino acid and fatty acid composition (%) of the analyzed samples were quantified with their relative area comparing with respective standards. In the present study, the leaf and corm of taro contained the three essential amino acids leucine, lysine and methionine. For the study, the calculated amino acid values were low in corm samples, but amino acid composition was higher in the leaf samples. Concerning fatty acids, the dominant fatty acid in the leaf and corm was oleic acid (C18:1, n-9) which ranged from 140.697 ± 0.054 to 216.775 ± 0.043 and 101.932 ± 0.023 to 101.950 ± 0. 04 mg/100 g, respectively. In the study, the fatty acid compositions in leaf were higher than the corm. This means that taro leaf would be considered as a good source of essential amino acid and fatty acid than the corm. Finally, from the proportion (mg/100 g) of saturated, monounsaturated and polyunsaturated fatty acids, the unsaturated fatty acids were the predominant fatty acids observed. The presence of high levels of unsaturated fatty acids in the entire investigation of our study taro is nutritionally rich.

Free amino acids of tymus after intragastric introduction of infesol40

Nutrition is one of the main factors that determine the functional activity of the components of the immune system and the deficiency of irreplaceable nutritional factors is the most common cause of immunodeficiency. The aim of the study was to analyze the concentrations of free amino acids and their nitrogen-containing metabolites after intragastric administration of Infezol40 in thymus tissues of rats. Materials and methods. The experiment was carried out on 30 rats that received intragastric Infezol40 in a dose of 20 ml/kg of body weight. The thymus tissue was used for the analysis. Determination of free amino acids was performed by reversedphase HPLC. Results and discussion. In all the studied periods, after the introduction of a mixture of amino acids in the thymus tissue the arginine/ornithine ratio and phosphoethanolamine/ethanolamine ratio decreased (due to an increase in the ethanolamine concentration), also the concentrations of essential amino acids methionine, phenylalanine and ornithine increased. Thus, enteral intake of amino acids has a pronounced effect on the metabolism of amino acids and the associated with it processes in the tissues of the thymus. The nature and severity of the observed changes suggest the presence of stimulation of proliferative processes in the thymus tissue, however, it is impossible to exclude the formation of an amino acid imbalance in this central organ of the immune system, which may be the cause of the subsequent development of immunodeficiency or disturbance of the processes of differentiation of cells of the immune system.

Defective methionine metabolism in the brain after repeated blast exposures might contribute to increased oxidative stress

Blast-induced traumatic brain injury (bTBI) is one of the major disabilities in Service Members returning from recent military operations. The neurobiological underpinnings of bTBI, which are associated with acute and chronic neuropathological and neurobehavioral deficits, are uncertain. Increased oxidative stress in the brain is reported to play a significant role promoting neuronal damage associated with both brain injury and neurodegenerative disorders. In this study, brains of rats exposed to repeated blasts in a shock tube underwent untargeted profiling of primary metabolism by automatic linear exchange/cold injection GC-TOF mass spectrometry and revealed acute and sub-acute disruptions in the metabolism of the essential amino acid methionine and associated antioxidants. Methionine sulfoxide, the oxidized metabolite of methionine, showed a sustained increase in the brain after blast exposure which was associated with a significant decrease in cysteine, the amino acid derived from methionine. Glutathione, the antioxidant synthesized from cysteine, also concomitantly decreased as did the antioxidant ascorbic acid. Reductions in ascorbic acid were accompanied by increased levels of its oxidized metabolite, dehydroascorbic acid and other metabolites such as threonic acid, isothreonic acid, glycolic acid and oxalic acid. Fluorometric analysis of the brains showed acute and sub-acute increase in total reactive oxygen species. In view of the fundamental importance of glutathione in the brain as an antioxidant, including its role in the reduction of dehydroascorbic acid to ascorbic acid, the disruptions in methionine metabolism elicited by blast exposure might prominently contribute to neuronal injury by promoting increased and sustained oxidative stress.

Land Productivity Enhancement by Sulfur Nutrient Management in Vertisol Rice Field

Sulfur is a secondary soil macro nutrients needed by plants as the most important part of the essential amino acids (cystine and methionine), protein synthesis, chlorophyll production and carbohydrate metabolism. The research aimed to study the land productivity improvement of Vertisol rice field by controlling the sulfur nutrient. The study was conducted in Dawu, Paron, and Guyung, Gerih, Ngawi, East Java, Indonesia, during the dry season 2013 and 2014. A randomized complete block design, with eight treatments and three replications were applied. The treatments were some rates of S-fertilizer application combined with in situ straw compost, ZA and Kieserit. Experimental plots dimension is 6 m x 5 m. Ciherang and Membramo were rice varieties grown in legowo 2:1 system. The results showed that S-fertilizer application can increase the weight of dry grain harvest and dry grain milled. The optimum doses of S-fertilizer were 24 kg S ha-1. Kieserit application resulted in less grain yield than ZA. Manure can increase the weight of dry grain harvest and tend to increase the weight of dry milled grain compared to those of the control treatments.

Liver steatosis and redox status alterations in obese Zucker rats

Obesity in the United States and other developed countries has been at epidemic proportions for more than two decades and continues to grow. The obese population has high comorbidity and mortality rates due to a variety of chronic diseases including cancer. The development of liver steatosis is a common consequence. This disease, ranging from simple hepatic steatosis and nonalcoholic steatohepatitis to cirrhosis, is a major health problem in the USA and worldwide. The negative effect of liver steatosis is recognized by its significant impact on the metabolic profile in humans. Our previous results demonstrated that obesity in Zucker rats was accompanied with an increase of oxidative and nitrosative stress in liver, perturbation of methylation (SAM/SAH) ratio and significant morphological changes in liver: increase in fatty steatosis to small foci of mononuclear infiltration. However, metabolic details that are leading to these changes in liver of obese rats are less known. Therefore, the objective of this study was to investigate the possible mechanisms that create such metabolic abnormalities. After one week of acclimation, six‐week old female lean (n=26) and obese (n=20) Zucker rats were fed AIN‐93 G diet and sacrificed 155 days later. Liver samples were snap frozen in liquid nitrogen and stored at −80° C until later. We used high sensitivity HPLC‐ECD and LC‐MS methods to assess the metabolic profile related to the methionine cycle and oxidative and nitrosative stress. Our results show that obese rats had significantly higher levels of essential amino acid Methionine (P<0.0001) and free Homocysteine (P<0.01) but lover level of free Cysteine (P<0.01) compared to lean rats. In contrast, the Cystine (oxidized Cysteine) and the Cystine/Cysteine (oxidative stress ratio), was significantly higher in obese rats (P <0.01 and P<0.001 respectfully) compared to lean rats. Additionally, obesity caused a significant (P<0.01) drop in liver HADPH/HADP ratio (redox ratio) and significant (P<0.02) drop in fHomocysteine/Methylation (methylation ratio). In summary, higher levels of oxidative/nitrosative stress in the liver of obese Zucker rats are the results of complex metabolic processes which include decreased levels of free reduced Cysteine as rate limiting amino acid in de‐novo Glutathione (GSH) synthesis; decreased reduction capacity (NADPH/NADP ratio) in liver what leads to lower rate of free Glutathione restoration from oxidized form (GSSG); increased intracellularly level of oxidized (GSSG, Cystine) products; reduction of methylation reactions activities (Homocysteine/Methionine ratio).Support or Funding InformationArkansas Biosicence Institute to RH and SM.

Determination of Total Sulfur, Sulfate, Sulfite, Thiosulfate, and Sulfolipids in Plants.

In response to oxidative stress the biosynthesis of the ROS scavenger, glutathione is induced. This requires the induction of the sulfate reduction pathway for an adequate supply of cysteine, the precursor for glutathione. Cysteine also acts as the sulfur donor for the sulfuration of the molybdenum cofactor, crucial for the last step of ABA biosynthesis. Sulfate and sulfite are, respectively, the precursor and intermediate for cysteine biosynthesis and there is evidence for stress-induced sulfate uptake and further downstream, enhanced sulfite generation by 5'-phosphosulfate (APS) reductase (APR, EC 1.8.99.2) activity. Sulfite reductase (SiR, E.C.1.8.7.1) protects the chloroplast against toxic levels of sulfite by reducing it to sulfide. In case of sulfite accumulation as a result of air pollution or stress-induced premature senescence, such as in extended darkness, sulfite can be oxidized to sulfate by sulfite oxidase. Additionally sulfite can be catalyzed to thiosulfate by sulfurtransferases or to UDP-sulfoquinovose by SQD1, being the first step toward sulfolipid biosynthesis.Determination of total sulfur in plants can be accomplished using many techniques such as ICP-AES, high-frequency induction furnace, high performance ion chromatography, sulfur combustion analysis, and colorimetric titration. Here we describe a total sulfur detection method in plants by elemental analyzer (EA). The used EA method is simple, sensitive, and accurate, and can be applied for the determination of total S content in plants.Sulfate anions in the soil are the main source of sulfur, required for normal growth and development, of plants. Plants take up sulfate ions from the soil, which are then reduced and incorporated into organic matter. Plant sulfate content can be determined by ion chromatography with carbonate eluents.Sulfite is an intermediate in the reductive assimilation of sulfate to the essential amino acids cysteine and methionine, and is cytotoxic above a certain threshold if not rapidly metabolized and can wreak havoc at the cellular and whole plant levels. Plant sulfite content affects carbon and nitrogen homeostasis Therefore, methods capable of determining sulfite levels in plants are of major importance. Here we present two robust laboratory protocols which can be used for sulfite detection in plants.Thiosulfate is an essential sulfur intermediate less toxic than sulfite which is accumulating in plants in response to sulfite accumulation. The complexity of thiosulfate detection is linked to its chemical properties. Here we present a rapid, sensitive, and accurate colorimetric method based on the enzymatic conversion of thiosulfate to thiocyanate.The plant sulfolipid sulfoquinovosyldiacylglycerol (SQDG) accounts for a large fraction of organic sulfur in the biosphere. Aside from sulfur amino acids, SQDG represents a considerable sink for sulfate in plants and is the only sulfur-containing anionic glycerolipid that is found in the photosynthetic membranes of plastids. We present the separation of sulfolipids from other fatty acids in two simple ways: by one- and two-dimensional thin-layer chromatography.

Investigation and application of photochemically induced direct UV detection of low or non-UV absorbing compounds by capillary electrophoresis

Some low or non-UV absorbing compounds like amino acids might be accessible to direct UV detection by capillary electrophoresis (CE), due to the photochemical reaction in the detection window of the separation capillary under extremely strong alkaline conditions. However, with regards to the photochemical reaction procedure and the influencing factors in CE, no comprehensive studies have been done. Herein, two strategies were applied to investigate the photochemical reaction mechanism including the introduction of an additional UV lamp and the utilization of driving pressure. The former confirmed the occurrence of photolysis, while the latter solved the interference of electroosmotic flow (EOF). Furthermore, the online photochemical reaction and online preconcentration technique were combined to develop a rapid, simple and sensitive method for determination of seven essential amino acids (valine, leucine, phenylalanine, methionine, tryptophan, threonine and lysine). Eventually, the developed method was successfully applied to the analysis of real samples with good reproducibility and reliability. This novel and simple method, based on the photochemical reactions occurring in the detection window and coupling with online preconcentration techniques, shows a great potential for the rapid and sensitive detection of low or non-UV absorbing compounds.

Proteome Remodeling in Response to Sulfur Limitation in "Candidatus Pelagibacter ubique".

The alphaproteobacterium "Candidatus Pelagibacter ubique" strain HTCC1062 and most other members of the SAR11 clade lack genes for assimilatory sulfate reduction, making them dependent on organosulfur compounds that occur naturally in seawater. To investigate how these cells adapt to sulfur limitation, batch cultures were grown in defined medium containing either limiting or nonlimiting amounts of dimethylsulfoniopropionate (DMSP) as the sole sulfur source. Protein and mRNA expression were measured before, during, and after the transition from exponential growth to stationary phase. Two distinct responses were observed, one as DMSP became exhausted and another as the cells acclimated to a sulfur-limited environment. The first response was characterized by increased transcription and translation of all "Ca. Pelagibacter ubique" genes downstream from the previously confirmed S-adenosyl methionine (SAM) riboswitches bhmT, mmuM, and metY. The proteins encoded by these genes were up to 33 times more abundant as DMSP became limiting. Their predicted function is to shunt all available sulfur to methionine. The secondary response, observed during sulfur-limited stationary phase, was a 6- to 10-fold increase in the transcription of the heme c shuttle-encoding gene ccmC and two small genes of unknown function (SAR11_1163 and SAR11_1164). This bacterium's strategy for coping with sulfur stress appears to be intracellular redistribution to support methionine biosynthesis rather than increasing organosulfur import. Many of the genes and SAM riboswitches involved in this response are located in a hypervariable genome region (HVR). One of these HVR genes, ordL, is located downstream from a conserved motif that evidence suggests is a novel riboswitch. IMPORTANCE "Ca. Pelagibacter ubique" is a key driver of marine biogeochemistry cycles and a model for understanding how minimal genomes evolved in free-living anucleate organisms. This study explores the unusual sulfur acquisition strategy that has evolved in these cells, which lack assimilatory sulfate reduction and instead rely on reduced sulfur compounds found in oxic marine environments to meet their cellular quotas. Our findings demonstrate that the sulfur acquisition systems are constitutively expressed but the enzymatic steps leading to the essential sulfur-containing amino acid methionine are regulated by a unique array of riboswitches and genes, many of which are encoded in a rapidly evolving genome region. These findings support mounting evidence that streamlined cells have evolved regulatory mechanisms that minimize transcriptional switching and, unexpectedly, localize essential sulfur acquisition genes in a genome region normally associated with adaption to environmental variation.