Arg Content Research Articles

New insights in integrated response mechanism of Lactobacillus plantarum under excessive manganese stress

As a natural inhabitant of gastrointestinal tract, Lactobacillus plantarum is well known for its health-promoting effects, especially in heavy metal-removal function. The response mechanism integrated physiology and proteomics of Lactobacillus plantarum under excessive manganese stress was systematically performed. More extracellular polymeric substance was secreted, whereas cells preferred to aggregate for resisting manganese stress. The stability of the membrane was maintained by up-regulating the proportion of unsaturated fatty acids, especially cyclopropane fatty acids. The contents of intracellular Asp and Arg, closely related with energy metabolism, decreased under excessive manganese stress. Comparative 2-DE proteomic analysis identified 52 proteins that significantly differed under different levels of manganese stress. The differentially expressed proteins, involved in the carbohydrate, amino acid, stress response and nucleotide metabolisms, were categorized as the crucial components during resisting manganese stress. Moreover, MntH 4 and MntH 5 were identified as the functional elements in regulation of manganese transportation model. The differential expression of six key transporter proteins under different manganese stresses indicated that the MntH 1, 2 and 3 was negatively regulated by MntR, while the regulation of MntH 4 and 5 presented the contrary model. Taken altogether, the study provides new insights into the response mechanism of probiotics to similar environmental stress.

Metabolism and distribution of pharmacological homoarginine in plasma and main organs of the anesthetized rat.

L-Homoarginine (hArg) and guanidinoacetate (GAA) are produced from L-arginine (Arg) by the catalytic action of arginine:glycine amidinotransferase. Guanidinoacetate methyltransferase methylates GAA on its non-guanidine N atom to produce creatine. Arg and hArg are converted by nitric oxide synthase (NOS) to nitric oxide (NO). NO is oxidized to nitrite and nitrate which circulate in the blood and are excreted in the urine. Asymmetric dimethylarginine (ADMA), an NOS inhibitor, is widely accepted to be exclusively produced after asymmetric N G-methylation of Arg residues in proteins and their regular proteolysis. Low circulating and urinary hArg concentrations and high circulating concentrations of ADMA emerged as risk markers in the human renal and cardiovascular systems. While ADMA's distribution and metabolism are thoroughly investigated, such studies on hArg are sparse. The aim of the present pilot study was to investigate the distribution of exogenous hArg in plasma, liver, kidney, lung, and heart in a rat model of takotsubo cardiomyopathy (TTC). hArg hydrochloride solutions in physiological saline were injected intra-peritoneally at potentially pharmacological, non-toxic doses of 20, 220, or 440mg/kg body weight. Vehicle (saline) served as control. As hArg has been reported to be a pro-oxidant, plasma and tissue malondialdehyde (MDA) was measured as a biomarker of lipid peroxidation. hArg administration resulted in dose-dependent maximum plasma hArg concentrations and distribution in all investigated organs. hArg disappeared from plasma with an elimination half-life ranging between 20 and 40min. hArg administration resulted in relatively small changes in the plasma and tissue content of Arg, GAA, ADMA, creatinine, and of the NO metabolites nitrite and nitrate. Remarkable changes were observed for tissue GAA, notably in the kidney. Plasma and tissue MDA concentration did not change upon hArg administration, suggesting that even high-dosed hArg is not an oxidant. The lowest hArg dose of 20mg/kg bodyweight increased 25-fold the mean hArg maximum plasma concentration. This hArg dose seems to be useful as the upper limit in forthcoming studies on the putative cardioprotective effects of hArg in our rat model of TTC.

Codon usage analysis of photolyase encoding genes of cyanobacteria inhabiting diverse habitats.

Nucleotide and amino acid compositions were studied to determine the genomic and structural relationship of photolyase gene in freshwater, marine and hot spring cyanobacteria. Among three habitats, photolyase encoding genes from hot spring cyanobacteria were found to have highest GC content. The genomic GC content was found to influence the codon usage and amino acid variability in photolyases. The third position of codon was found to have more effect on amino acid variability in photolyases than the first and second positions of codon. The variation of amino acids Ala, Asp, Glu, Gly, His, Leu, Pro, Gln, Arg and Val in photolyases of three different habitats was found to be controlled by first position of codon (G1C1). However, second position (G2C2) of codon regulates variation of Ala, Cys, Gly, Pro, Arg, Ser, Thr and Tyr contents in photolyases. Third position (G3C3) of codon controls incorporation of amino acids such as Ala, Phe, Gly, Leu, Gln, Pro, Arg, Ser, Thr and Tyr in photolyases from three habitats. Photolyase encoding genes of hot spring cyanobacteria have 85% codons with G or C at third position, whereas marine and freshwater cyanobacteria showed 82 and 60% codons, respectively, with G or C at third position. Principal component analysis (PCA) showed that GC content has a profound effect in separating the genes along the first major axis according to their RSCU (relative synonymous codon usage) values, and neutrality analysis indicated that mutational pressure has resulted in codon bias in photolyase genes of cyanobacteria.

Standardized ileal digestible amino acid contents of canola meal from Canadian crushing plants for growing pigs.

Studies have shown that there are variations in the chemical and nutritive composition of canola meal (CM) produced in Canada, some of which may result from differences among the canola seed crushing plants. Therefore, it is necessary to determine the variability in the nutritive value of CM as its end users desire increased meal consistency and more information on any potential variability in AA digestibility. Thus, 18 ileal cannulated barrows (average initial BW = 23.3 kg) were used to determine the apparent (AID) and standardized (SID) ileal digestibility of N and AA and standardized ileal digestible N and AA contents in CM from 6 processing plants in Canada. Two processing plants provided CM in both mash and pellet forms, whereas the other 4 provided it only in mash form, giving a total of 8 CM samples. The barrows were fed 9 cornstarch-based diets. The first 8 diets were formulated to contain the CM samples as the only source of AA. The ninth diet was a casein-cornstarch diet to determine ileal endogenous AA losses. All diets contained 0.3% titanium dioxide as an indigestible marker. Pigs were housed individually in pens and were fed the 9 diets in a completely randomized design for 3 periods to give 6 pigs per diet. Each experimental period lasted for 7 d, consisting of 5 d of adaptation and 2 d of ileal digesta collection at 2-h intervals from 0800 to 2000 h on d 6 and 7. There was an effect ( < 0.05) of CM source on 1) the AID of N, Met, Cys, Thr, Val, Gly, and Ser; 2) the SID of N, Met, and Cys; and 3) the standardized ileal digestible content of all AA. Pelleting reduced ( < 0.05) the standardized ileal digestible content of Arg, Ile, Glu, and Gly in 1 of the CM samples tested and of all AA except His in the other CM sample. The SID values for Arg, Lys, Met, and Thr averaged 87.2%, 78.2%, 84.5%, and 74.1%, respectively. The standardized ileal digestible contents of Arg, Lys, Met, and Thr averaged 2.10%, 1.71%, 0.50%, and 1.01%, respectively. In conclusion, there were variations in the AID, SID, and standardized ileal digestible AA contents of CM among crushing plants in Canada.

Expression of CphB- and CphE-type cyanophycinases in cyanophycin-producing tobacco and comparison of their ability to degrade cyanophycin in plant and plant extracts.

Increasing the arginine (Arg) content in plants used as feed or food is of interest, since the supplementation of food with conditionally essential Arg has been shown to have nutritional benefits. An increase was achieved by the expression of the Arg-rich bacterial storage component, cyanophycin (CGP), in the chloroplast of transgenic plants. CGP is stable in plants and its degradation into β-aspartic acid (Asp)-Arg dipeptides, is solely catalyzed by bacterial cyanophycinases (CGPase). Dipeptides can be absorbed by animals even more efficiently than free amino acids (Matthews and Adibi 1976; Wenzel et al. 2001). The simultaneous production of CGP and CGPase in plants could be a source of β-Asp-Arg dipeptides if CGP degradation can be prevented in planta or if dipeptides are stable in the plants. We have shown for the first time that it is possible to co-express CGP and CGPase in the same plant without substrate degradation in planta by transient expression of the cyanobacterial CGPase CPHB (either in the plastid or cytosol), and the non-cyanobacterial CGPase CPHE (cytosol) in CGP-producing Nicotiana tabacum plants. We compared their ability to degrade CGP in planta and in crude plant extracts. No CGP degradation appeared prior to cell homogenization independent of the CGPase produced. In crude plant extracts, only cytosolic CPHE led to a fast degradation of CGP. CPHE also showed higher stability and in vitro activity compared to both CPHB variants. This work is the next step to increase Arg in forage plants using a stable, Arg-rich storage protein.

Influence of wet heating and autoclaving on chemical composition and standardized ileal crude protein and amino acid digestibility in full-fat soybeans for pigs.

One batch each of eight full-fat soybeans (FFSB) was used to determine the effect of different heat treatments including wet heating (WH) and autoclaving (AC) on chemical composition and standardized ileal digestibility (SID) of CP and AA in growing pigs. The raw FFSB (K0) were either treated by WH at 80°C for 1 min (K1), at 100°C for 6 min (K2), or at 100°C for 16 min (K3). Thereafter, these batches were expanded at 125°C for 15 s. A further heat treatment included AC at 110°C for 15 (Z1), 30 (Z2), 45 (Z3), or 60 (Z4) min of FFSB that were subjected to the same WH treatment as K3. Diets were formulated to contain the respective FFSB as the sole source of CP and AA. A N-free diet was used to measure basal endogenous losses of CP and AA in an additional period at the end of the experiment. Eight ileally cannulated pigs (28 ± 1 kg) were allocated to a row-column design with 8 diets and 6 periods of 7 d each. An increase in the duration of WH had no effect on contents of AA (% of CP) and NDF, but NDIN contents linearly increased ( < 0.05) with increasing time for WH. Autoclaving resulted in a linear decrease ( < 0.05) of trypsin inhibitor activity (TIA), contents of Arg, Leu, Ala, Asp, Cys, and Gly as well as Lys to CP ratio (Lys:CP), reactive Lys to CP ratio (rLys:CP), and in an increase ( < 0.05) in contents of NDF and NDIN. There was a quadratic response ( < 0.05) of SID of CP and AA as time for WH at 100°C increased from 0 (K0) to 6 (K2) up to 16 (K3) min. Moreover, a quadratic response ( < 0.05) to increasing time of AC was observed for SID of Arg, Phe, and Pro. The SID of CP and all indispensable AA showed a quadratic response ( < 0.05) to decreasing TIA, urease activity, protein solubility in 0.2% potassium hydroxide, protein dispersibility index, Lys:CP, (lightness), and to increasing NDIN and (redness). In addition, there was a linear increase ( < 0.05) in SID values with decreasing rLys:CP and increasing NDF contents. In conclusion, WH proved to be suitable for increasing SID values. Further improvement of SID of most AA could be achieved on additional AC treatment from Z1 to Z3, however, it needs to be considered, if the observed increase due to AC is cost effective in view of the additional production costs. Several chemical and physical parameters can be used in the feed industry for quality control purposes to predict the extent of heat damage on SID of CP and indispensable AA in FFSB.

Effect of a high-concentrate diet on milk components and mammary health in Holstein dairy cows

In order to evaluate the milk yield, milk quality, and health of dairy cows fed a high-concentrate (HC) diet, eight lactating Holstein dairy cattle were randomly assigned to HC or low-concentrate (LC) diet groups and fed for 50 days, and the auto-control studying before and after treatment with the two diets was used. During the experiment, plasma and milk samples were collected and measured. With regard to milk component, HC feeding led to higher milk production (P < 0.05), but significantly lower milk protein percentage (P < 0.05), milk protein yield (P < 0.05), and milk fat percentage (P < 0.05) throughout the five periods than LC feeding. Milk somatic cell count and N-acetyl-D-glucosaminidase activity (P < 0.01) were higher than those observed under LC feeding. mRNA expression levels of interleukin-8 (IL-8), C-C motif chemokine ligand (CCL5), and lactalbumin alpha (α-LA) were investigated by qPCR and found to be significantly lower (P < 0.01) in cattle fed the HC diet. The amino acid content was analyzed by high performance liquid chromatography (HPLC), and the content of Asp (P < 0.01), Gln (P < 0.01), Ala (P < 0.05), Leu (P < 0.05), Lys (P < 0.05), and Ile (P < 0.01) was significantly lower in the HC group, whereas the content of Arg (P < 0.05) and Phe (P < 0.01) was significantly higher. These results suggest that the HC diet might have an important influence on mammary health. The amino acid content was lower, suggesting that depletion of amino acids, resulting in depleted milk protein, affects milk quality.

Nitric oxide-polyamines cross-talk during dormancy release and germination of apple embryos

Nitric oxide (NO) and polyamines (PAs) belong to plant growth and development regulators. These compounds play a key role in numerous physiological processes e.g. seed germination. Based on the suggestion of overlapping of NO and PAs biosynthetic pathways, we demonstrated a cross-talk of NO and PAs in regulation of embryonic dormancy release. The aim of the work was to investigate an impact of PAs (Put, Spd and Spm) or NO short-term fumigation on nitrite, urea, Arg and ornithine (Orn) content, NO synthase-like (NOS-like) and arginase activity in axes of apple (Malus domestica Borkh.) embryos during dormancy alleviation and at the stage of termination of germination sensu stricto. NO, Put/Spd induced dormancy breakage and germination of apple embryos corresponded to stimulation of urea cycle and high free Arg pool in seedlings roots. After two days of the culture Put and Spd stimulated Arg dependent NO formation, inhibition of which was observed after Spm application. Put or Spd application as well as NO short-term pretreatment of apple embryos influenced level of ubiquitin-conjugated proteins. Higher abundance of such modified proteins correlated well to the declined content of nitrated proteins, suggesting their important role in regulation of embryo germination. NO led to stimulation of embryos germination by increasing level of free PAs (mostly Put). While transcriptomic approach showed down regulation of Spm synthesis and up-regulation of Spm degradation by NO, confirming negative role of Spm over-accumulation in embryo dormancy removal. Our data clearly indicate positive relationship of NO-Put/Spd acting as dormancy removing factors.

Specific amino acids responsible for the cold adaptedness of Micrococcus antarcticus β-glucosidase BglU.

Psychrophilic enzymes display efficient activity at moderate or low temperatures (4-25°C) and are therefore of great interest in biotechnological industries. We previously examined the crystal structure of BglU, a psychrophilic β-glucosidase from the bacterium Micrococcus antarcticus, at 2.2Å resolution. In structural comparison and sequence alignment with mesophilic (BglB) and thermophilic (GlyTn) counterpart enzymes, BglU showed much lower contents of Pro residue and of charged amino acids (particularly positively charged) on the accessible surface area. In the present study, we investigated the roles of specific amino acid residues in the cold adaptedness of BglU. Mutagenesis assays showed that the mutations G261R and Q448P increased optimal temperature (from 25 to 40-45°C) at the expense of low-temperature activity, but had no notable effects on maximal activity or heat lability. Mutations A368P, T383P, and A389E significantly increased optimal temperature (from 25 to 35-40°C) and maximal activity (~1.5-fold relative to BglU). Thermostability of A368P and A389E increased slightly at 30°C. Mutations K163P, N228P, and H301A greatly reduced enzymatic activity-almost completely in the case of H301A. Low contents of Pro, Arg, and Glu are important factors contributing to BglU's psychrophilic properties. Our findings will be useful in structure-based engineering of psychrophilic enzymes and in production of mutants suitable for a variety of industrial processes (e.g., food production, sewage treatment) at cold or moderate temperatures.

Variation of Amino Acids in the Muscle of Crab Portunus sanguinolentus During Storage

Amino acids are at the basis of all life processes, as they are absolutely essential for every metabolic process. In the present study variation of amino acids in the muscle of the crab Portunus sanguinolentus during frozen storage was analyzed. In the freshly caught crabs the levels of Glycine and Arginine were the highest, followed by glutamine (Gln) Ala and proline (Pro) together they accounted for 83% of the total amount of FAA. Taurine (Tau) and Glu were also in fairly large amounts. High levels of Gly, Arg, Pro, Tau and Ala are generally present in the muscle of crabs. The P. sanguinolentus muscle was also rich in Gln but low in Tau. The total amount of FAA altered slight throughout storage, but increased by 24-38% prior to the preliminary decomposition stage. The overall quantity of Arg, Gly, Ala and Glu before storage averaged 1272 mg/100 g. the total amount of these four taste-active amino acids increased by12-48% within 4 days of storage at 4°C, but hardly reduced after storage. Significant differences, except glutamic acid and tyrosine, were observed among the amino acid values changed during storage at 4°C. Major FAA such as Gly, Ala, Pro, Gln, Arg and Tau also increased, whereas, their levels usually exhibited small changes or even a decrease except that the Arg and Tau contents increased to some extent. The Glu content fluctuated during the early storage periods but its level reduced after 1 day of storage.

Dietary Arginine Requirements are Dependent on the Rate of Citrulline Production in Mice

In many species, including humans, arginine (Arg) is considered a semi‐essential amino acid because under certain conditions endogenous synthesis cannot meet its demand. The requirements of Arg for growth in mice are ill defined and seem to vary depending on the genetic background of the animals. For this reason, Institute of Cancer Research (ICR) and C57BL/6J (BL6) mice were fed diets with increasing Arg content between 24 and 42d of life to determine the Arg requirements for growth. 'De novo' Arg synthesis and the production of its precursor, citrulline (Cit), were measured using stable isotopes. ICR mice were heavier than BL6 mice (12.1±0.20 vs. 8.7±0.11 g, P &lt; 0.001) at weaning (d21) and displayed a greater growth rate (0.66±0.04 g/d and 0.46±0.03 g/d, P &lt; 0.001). Whereas ICR mice grew at the same rate regardless of the Arg content of the diet (P = 0.80), BL6 mice showed a reduction in growth rate when fed the diet devoid of Arg (Arg sufficient diet 0.46±0.03 vs. Arg free diet 0.25±0.02 g/d, P &lt; 0.001). Breakpoint analysis showed that on average, BL6 mice require 2.32±0.39 g Arg/kg diet to maximize weight gain. A reduced expression of ornithine transcarbamylase in the small intestine of BL6 mice (0.15±0.0 vs ICR 1±0.2 arbitrary units, P &lt; 0.001) was responsible for the lower rate of Cit production observed in BL6 mice (96±5 vs ICR 123±9 µmol•kg‐1•h‐1, P &lt; 0.002), which translated into a reduced 'de novo' Arg synthesis (P &lt; 0.001) and explains why this strain has a requirement for Arg. Our data indicates that variability in the production of Cit and endogenous synthesis of Arg determined the need for dietary Arg to meet the requirements for growth. This indicates that in mice Arg is an essential amino acid for growth, at least for some genetic backgrounds.

Penicillium–sesame interactions: A remedy for mitigating high salinity stress effects on primary and defense metabolites in plants

Salinization of agricultural land is increasing, and reduces the yield of crop plants. The introduction of plant growth-promoting and salt-tolerant microbes to soil can protect plants from salt effects. This study examined the primary and defense metabolites in sesame plants associated with Penicillium sp. NICS01, which mitigates oxidative stress induced by high salinity. Salt tolerance in Penicillium sp. NICS01 was observed in medium supplemented with 5.0% and 7.5% NaCl. The role of this fungus in mitigating against high salinity (150mM NaCl) was tested on salt-stressed sesame plants. Salt stress decreased the length and weight of sesame shoots, but applying Penicillium sp. NICS01 significantly (p≤0.05) increased these parameters in plants grown under salt-stress conditions by enhancing photosynthetic pigment levels (chlorophylls and carotenoids), sugar concentrations (sucrose, glucose, and fructose), fatty acid contents (palmitic acid, linolenic acid, arachidic acid, and cis-11-eicosenoic acid), and ionic transport (K and Ca, (p≤0.05)). In addition, salt-induced oxidative damage was reduced by lowered lipid peroxidation (5%) and salicylic acid (15%) and Na (18%) contents, and raised peroxidase activity (more than five-fold), while amino acid (Thr, Gly, Val, Met, Ile, Leu, Tyr, Phe, Arg, Asp, Ser, Asn, Glu, Ala, and GABA) synthesis was regulated by the fungal interaction. Asp, Thr, Ser, Glu, Ala, and Arg contents were significantly (p≤0.05) enhanced in salinity affected plants due to the effect of fungal inoculation. Our findings revealed that Penicillium sp. NICS01 regulates the biosynthesis of primary and defense metabolites in sesame plants under salt stress, suggesting that this fungus can ameliorate damage caused by salt stress in crop plants.

Antioxidant capacity of hydrolyzed animal by-products and relation to amino acid composition and peptide size distribution.

The antioxidative capacity of six different tissue hydrolysates (porcine colon, heart and neck and bovine lung, kidney and pancreas) were tested by three different assays monitoring iron chelation, ABTS radical scavenging and inhibition of lipid oxidation in emulsions, respectively. The hydrolysates were also investigated with respect to amino acid composition and peptide size distribution. The hydrolysates contained peptides ranging from 20kDa to below 100Da with a predominance of peptides with low molecular weight (53.8 to 89.0% below 3kDa). All hydrolysates exhibited antioxidant activity as assessed with all three methods; inhibition of lipid oxidation ranging from 72 to 88% (at a final protein concentration of 7mg/mL), iron chelation capacity from 23 to 63% (at 1.1mg/mL), and ABTS radical scavenging from 38 to 50% (at 10μg /mL). The antioxidant activity did not correlate with the proportion of low molecular weight peptides in the hydrolysed tissues, but with the content of specific amino acid residues. The ABTS radical scavenging capacity of the tissues was found to correlate with the content of Trp, Tyr, Met and Arg, whereas the ability to inhibit the oxidation of lineoleic acid correlated with the content of Glu and His. The chosen animal by-products thus represent a natural source of antioxidants with potential for food application.

Impact of sodium chloride replacement by salt substitutes on the proteolysis and rheological properties of dry fermented sausages

The effect of a 50% reduction of NaCl and its replacement by KCl, CaCl2, and a blend of KCl and CaCl2 (1:1) on the proteolysis and rheological properties of dry fermented sausages was investigated. The reduction or replacement of NaCl by KCl did not cause changes in the electrophoretic profile and the addition of CaCl2 decreased the degradation of sarcoplasmic proteins during the manufacturing process. Samples with a 50% reduction of NaCl showed a higher content of the amino acids Arg, Glu, His, Val, Cys, Lys, and Trp, whereas the samples containing CaCl2 had a higher content of the amino acids Asp, Thr, Ala, Met, Leu, Ile, and Phe. The reduction or replacement of NaCl by KCl decreased sample firmness, whereas the addition of CaCl2 increased the hardness of the samples.

Dietary supplementation with yeast product improves intestinal function, and serum and ileal amino acid contents in weaned piglets

Weaning is associated with impairments in intestinal and immune function, and dietary supplementation with yeast products can improve the intestine mucosal structure and stimulate the immune system of weaned piglets. The present study was conducted to test the hypothesis that dietary supplementation with yeast product may regulate immunoglobulin production by improving intestinal function and nutrient levels in weaned piglets. Eighteen piglets weaned at 21 days of age were randomly assigned to receive 1 of 3 treatments consisting of a basal diet (control), the basal diet supplemented with 1.2g/kg of yeast product (yeast product) or the basal diet supplemented with 20mg/kg of colistin sulphate (antibiotic) for 14 days. Dietary yeast product or antibiotic supplementation enhanced (P<0.05) duodenal and ileal mucosal sIgA as well as serum total protein, IgG, and IgM contents in weaned piglets. Piglets that were fed a diet that contained yeast product had greater (P<0.05) serum Ile, Leu, Phe, and Pro contents than control piglets. The contents of Arg, His, Leu, Lys, Trp, Val, Ser, Glu, Gln, and Pro in the ileal mucosa of weaned piglets were also increased (P<0.05) when yeast products were included in the diet. Consistent with the increases in amino acid (AA) contents, the activity of alkaline phosphatase and the expression of AA transporters were both increased (P<0.05) in the ileum of piglets that were fed a diet that contained yeast product. These findings indicate that yeast product may enhance immunoglobulin production by improving intestinal function and the levels of nutrients in weaned piglets, which suggests that yeast product might be an alternative to the use of antibiotics in diets for weaning piglets.

A putative Δ1-pyrroline-5-carboxylate synthetase involved in the biosynthesis of proline and arginine in Leptinotarsa decemlineata

Delta 1-pyrroline-5-carboxylate synthetase (P5CS) catalyzes the conversion of glutamate (Glu) to Glu semialdehyde (GSA). GSA spontaneously cyclizes to form P5C. P5C is then reduced to proline (Pro) or is converted to ornithine, the intermediate for arginine (Arg) biosynthesis. In the present study, a full-length Ldp5cs complementary DNA was cloned from the Colorado potato beetle Leptinotarsa decemlineata, a notorious insect defoliator of potato in most potato-growing regions of the world. Ldp5cs encodes a 792-amino-acid protein which shares high identity to homologues from other insect species. Quantitative reverse transcription polymerase chain reaction revealed that Ldp5cs was ubiquitously expressed in the eggs, first to fourth-instar larvae, wandering larvae, pupae and sexually mature adults. In the adults, Ldp5cs mRNA levels were higher in the fat body, foregut, midgut and hindgut, moderate in the ventral ganglion, lower in the thorax muscles, epidermis and Malpighian tubules. Two double-stranded RNAs (dsRNAs) (dsLdp5cs1 and dsLdp5cs2) targeting Ldp5cs were constructed and bacterially expressed. Ingestion during 3 consecutive days of dsLdp5cs1 or dsLdp5cs2 successfully silenced Ldp5cs, significantly reduced the contents of Pro and Arg in the hemolymph, decreased flight speed and shortened flight distance of the resulting adults. Furthermore, knocking down Ldp5cs significantly increased adult mortality. Thus, our results suggest that identified Ldp5cs encodes a functional P5CS enzyme that is involved in the biosynthesis of Pro and Arg in L. decemlineata.

Nutrient analysis, metabolizable energy, and digestible amino acids of soybean meals of different origins for broilers

Nutrient composition, ileal amino acid (AA) digestibility, and AME of 55 soybean meal (SBM) samples from the United States (US; n = 16), Argentina (ARG; n = 16), Brazil (BRA; n = 10), and India (IND; n = 13), collected from commercial mills in Southeast Asia, were compared using laboratory analyses and animal studies. There were significant (P < 0.05 to 0.001) differences due to origin in CP, fat, ash, fiber, and nonstarch polysaccharide (NSP) contents of SBM. The average CP content of US, ARG, BRA, and IND samples was determined to be 47.3, 46.9, 48.2, and 46.4% (as-fed basis), respectively. Compared with SBM from other origins, crude fiber and NSP contents were lower (P < 0.05) and sucrose content was higher (P < 0.05) in the US samples. The IND samples had the highest (P < 0.05) contents of fiber, ash, and NSP, and lowest (P < 0.05) contents of fat and sucrose. Differences (P < 0.0001) were observed among origins for in vitro protein quality measures (urease index, KOH protein solubility, and trypsin inhibitor activity). Significant (P < 0.001) effects due to origin were observed for all minerals. Soybean meal from the US and IND had higher (P < 0.05) calcium contents (0.45%) compared with those from ARG and BRA (0.28–0.31%). Phosphorus and potassium contents were lowest (P < 0.05) in SBM from IND, and no differences (P > 0.05) were observed in SBM from other origins. Iron content was markedly high (928 mg/kg) in SBM from IND compared with those from other origins (103–134 mg/kg). Major origin-related differences (P < 0.0001) were observed in the AME of SBM. The average AME content of US, ARG, BRA, and IND samples was 2,375, 2,227, 2,317, and 2,000 kcal/kg (as-fed basis), respectively. Total AA contents of US, ARG, BRA, and IND samples were similar (P > 0.05) for 9 of the 17 amino acids. Major differences (P < 0.05 to P < 0.001) due to origin were determined for the digestibility of all AA. The IND samples had the lowest (P < 0.05) digestibility and no differences (P > 0.05) between samples from other 3 origins. However, the digestible CP content of US SBM was higher (P < 0.05) than those of ARG and IND, but similar (P > 0.05) to that from BRA. The digestible CP contents of SBM from the US, ARG, BRA, and IND were 40.0, 38.6, 39.8, and 36.7%, respectively. Digestible contents of indispensable AA, in general, followed the same trend as that of digestible CP. In conclusion, the present evaluation showed that major differences in nutritive value do exist between SBM from different origins in terms of nutrient contents, AME, and digestible AA. Overall, SBM originating from the US had better nutritive value compared with those from ARG and IND, on the basis of AME and contents of digestible CP and digestible AA.

Parental effects on nutritional and antioxidants constituents in seeds of peanut cv. Boreom 1

In spite of the importance of parental inheritance effects, many aspects remain inadequately explained. The objective of this study was to explore parental effects on their progeny by estimating the variability of nutritional content in peanut seeds. The peanut cv. Boreom 1 was derived from Suwon 108 (female) and Milyang 4 (male). Protein and amino acid analyses revealed that male and female parent influences on protein, Asp, Thr, Ser, Glu, Pro, Ala, Cys, Val, Met, Ile, Leu, Tyr, Phe, His, and Arg content in their progeny. The oil and fatty acid composition (C16:0, C18:0, C18:1, C18:2, C20:0, C20:1, and C22:0) of the progeny were controlled by both parental types. The synergistic interaction of female and male parental genes was also shown on sucrose and stachiyose content, while paternal effect was found on raffinose in their progeny. The antioxidant activity, daidzin, glycitin, genistin, mal-glycitin, maldaidzin, mal-genistin, and daidzein content of Boreom 1 were significantly correlated with those secondary metabolites of female parent. Our results documented that both parental genes differentially influenced on nutritional composition of their progeny, Boreom 1. This biochemical evidence of parental effects would be support to identify the suitable cultivars to improve the crop breeding.

Light chain editors of anti-DNA receptors in human B cells

Receptor editing is a mechanism of self-tolerance used in newly generated B cells. The expressed heavy (H) or light (L) chain of an autoreactive receptor is replaced by upstream V genes which eliminate or modify autoreactivity. Editing of anti-DNA receptors has been characterized in anti-DNA transgenic mouse models including 3H9, 3H9/56R, and their revertant 3H9GL. Certain L chains, termed editors, rescue anti-DNA B cells by neutralizing or modifying DNA binding of the H chain. This editing mechanism acts on the natural H chain repertoire; endogenous H chains with anti-DNA features are expressed primarily in combination with editor L chains. We ask whether a similar set of L chains exists in the human repertoire, and if so, do they edit H chains with anti-DNA signatures? We compared the protein sequences of mouse editors to all human L chains and found several human L chains similar to mouse editors. These L chains diminish or veto anti-DNA binding when expressed with anti-DNA H chains. The human H chains expressed with these L chains also have relatively high arginine (Arg) content in the H chain complementarity determining region (H3), suggesting that receptor editing plays a role in establishing tolerance to DNA in humans.

Influence of hydrophilic amino acids and GC-content on expression of recombinant proteins used in vaccines against foot-and-mouth disease virus in Escherichia coli

Epitope-based protein expression in Escherichia coli can be improved by adjusting its amino acid composition and encoding genes. To that end, we analyzed 24 recombinant epitope proteins (rEPs) that carry multiple epitopes derived from VP1 protein of foot-and-mouth disease virus. High level expression of the rEPs was attributed to a high content of Arg, Asn, Asp and Thr, a low content of Gln, Pro and Lys, a high content of hydrophilic amino acids and a higher isoelectric point value resulting from abundant Arg. It is also attributed to the appropriate guanine and cytosine content in the encoding genes. The data provide a reference for adjusting the amino acid composition in designing epitope-based proteins used in vaccines and for adjusting the synonymous codons to improve their expressions in E. coli.