Bacidina genus novum familiaeLecideaceae s. lat. (Ascomycetes lichenisati)

The following eleven species currently classified in the generaBacidia s. lat. andCatillaria s. lat. are transferred to the new genusBacidina Vězda gen. n. (Lecideaceae s. lat.):Bacidina apiahica (Müll. Arg.) comb. n.,B. chloroticula (Nyl.)Vězda etPoelt comb. n.,B. egenula (Nyl.) comb. n.,B. inundata (Fr.) comb. n.,B. mirabilis (Vězda) comb. n.,B. neglecta (Vězda) comb.n.,B. pallidocarnea (Müll. Arg.) comb. n.,B. phacodes (Koerb.) comb.n.,B. scutellifera (Vězda) comb.n.,B. vasakii (Vězda) comb.n., andB. ziamensis (Vězda) comb.n.     

Different vasoactive effects of chronic endothelial and neuronal NO-synthase inhibition in young Wistar rats

While the unequivocal pattern of endothelial nitric oxide synthase (eNOS) inhibition in cardiovascular control is recognized, the role of NO produced by neuronal NOS (nNOS) remains unclear. The aim of this study was to compare the effects of chronic treatment with 7-nitroindazole (7-NI, nNOS inhibitor) and N^G-nitro-l-arginine methylester (l-NAME, general and predominantly eNOS inhibitor) on cardiovascular system of young normotensive rats. Wistar rats (4 weeks old) were used: controls and rats administered either 7-NI (10 mg/kg bw/day) or l-NAME (50 mg/kg bw/day) in drinking water for 6 weeks. The systolic blood pressure (sBP) was measured by plethysmographic method, and the vasoactivity of isolated arteries was recorded. 7-NI-treatment did not affect sBP; however, the sBP was increased after l-NAME-treatment. l-NAME inhibited acetylcholine-induced relaxation of thoracic aorta (TA), whereas it remained unchanged after 7-NI-treatment. The response of TA to sodium nitroprusside was increased in both experimental groups. The expression of eNOS and nNOS in TA was unchanged in both experimental groups, whereas the activity of NOS was decreased in l-NAME-treated group. Noradrenaline- and angiotensin II-induced contractions of TA were reduced in l-NAME-treated group; however, the contractions remained unchanged in 7-NI-treated group. In all groups, the endogenous angiotensin II participated in adrenergic contraction of TA; this contribution was significantly increased in l-NAME-treated group. Neurogenic contractions in mesenteric artery (MA) remained unchanged after 7-NI-treatment, but increased after l-NAME-treatment. Results show that NO deficiency induced by administration of 7-NI and l-NAME had different cardiovascular effects: eNOS and nNOS triggered distinct signaling pathways in young normotensive rats.     

Hydrolysis of the Leu-Gly bond of phenylazobenzyl-oxycarbonyl-l-Pro-l-Leu-Gly-l-Pro-D-Arg (a substrate of microbial collagenases) by treponemes isolated from the subgingival plaque of periodontitis patients

Cell extracts prepared from several oral treponemes isolated from the subgingival plaque of periodontitis patients showed high enzyme activity toward phenylazobenzyl-oxycarbonyl-l-prolyl-l-leucylglycyl-l-prolyl-d-arginine (a compound used as a substrate for microbial collagenases). One major enzyme hydrolyzing this substrate at the Leu-Gly bond only was partially purified from an unspeciated treponeme (strain US),Treponema denticola ATCC 35405, and 29 different clinical isolates ofT. denticola. TheTreponema US enzyme also hydrolyzed furylacryloyl-l-leucylglycyl-l-prolyl-l-alanine (another substrate of bacterial collagenases) at the Leu-Gly bond. This enzyme also hydrolyzed various collagens and collagen-derived peptides. These treponemal proteases were sensitive to metal chelators andp-chloromercury compounds. The results indicate that human oral treponemes contain enzymes that readily hydrolyze in chromogenic protease substrates the Leu-Gly bond only that is the cleavage site of these substrates also by “true” microbial collagenases.     

Metabolic engineering Corynebacterium glutamicum for the l-lysine production by increasing the flux into l-lysine biosynthetic pathway

The experiments presented here were based on the conclusions of our previous results. In order to avoid introduction of expression plasmid and to balance the NADH/NAD ratio, the NADH biosynthetic enzyme, i.e., NAD-dependent glyceraldehyde-3-phosphate dehydrogenase (GADPH), was replaced by NADP-dependent GADPH, which was used to biosynthesize NADPH rather than NADH. The results indicated that the NADH/NAD ratio significantly decreased, and glucose consumption and l-lysine production drastically improved. Moreover, increasing the flux through l-lysine biosynthetic pathway and disruption of ilvN and hom, which involve in the branched amino acid and l-methionine biosynthesis, further improved l-lysine production by Corynebacterium glutamicum. Compared to the original strain C. glutamicum Lys5, the l-lysine production and glucose conversion efficiency (α) were enhanced to 81.0 ± 6.59 mM and 36.45 % by the resulting strain C. glutamicum Lys5-8 in shake flask. In addition, the by-products (i.e., l-threonine, l-methionine and l-valine) were significantly decreased as results of genetic modification in homoserine dehydrogenase (HSD) and acetohydroxyacid synthase (AHAS). In fed-batch fermentation, C. glutamicum Lys5-8 began to produce l-lysine at post-exponential growth phase and continuously increased over 36 h to a final titer of 896 ± 33.41 mM. The l-lysine productivity was 2.73 g l^?1 h^?1 and the α was 47.06 % after 48 h. However, the attenuation of MurE was not beneficial to increase the l-lysine production because of decreasing the cell growth. Based on the above-mentioned results, we get the following conclusions: cofactor NADPH, precursor, the flux through l-lysine biosynthetic pathway and DCW are beneficial to improve l-lysine production in C. glutamicum.     

Putrescine enhances chilling tolerance of tomato (Lycopersicon esculentum Mill.) through modulating antioxidant systems

Seedlings of two tomato (Lycopersicon esculentum Mill.) cultivars, cv. Mawa (chilling-resistant) and cv. Moneymaker (chilling-sensitive) were used to investigate the effects of exogenous putrescine (Put) on chilling tolerance as well as on changes of physiological features and the fluctuation of free and conjugated endogenous polyamines (PAs) contents in the leaves under chilling stress. During chilling stress, accumulation of hydrogen peroxide (H₂O₂) was obviously detected in the leaves of both cultivars, but it was fewer in cv. Mawa. Meanwhile, d-arginine (d-Arg), a Put biosynthesis inhibitor caused more H₂O₂ accumulation in both cultivars, especially in cv. Moneymaker. By adding back Put to leaves, accumulation of H₂O₂ obviously reduced in two cultivars. Put was also involved in the increase of Fv/Fm and the decrease of malondialdehyde (MDA) in two cultivars under chilling stress. Despite the two cultivars displaying differential behavior towards enzymic antioxidants, enzymes and components of the ascorbate–glutathione (AsA–GSH) cycle in responses to chilling stress, d-Arg treatment diminished the enzyme activities and antioxidant contents induced by chilling stress and its reversion was performed by adding Put in both cultivars. During chilling stress, free and conjugated endogenous PA contents increased in two cultivars. d-Arg treatment inhibited the increases, and exogenously applied Put enhanced the increases in two cultivars. These results suggested that Put played important roles in the tolerance of tomato against chilling stress, which was most likely achieved by modulating antioxidant system as well as increasing free and conjugated PAs.     

Identification and characterization of a short-chain acyl dehydrogenase from Klebsiella pneumoniae and its application for high-level production of l-2,3-butanediol

Klebsiella pneumoniae synthesize large amounts of l-2,3-butanediol (l-2,3-BD), but the underlying mechanism has been unknown. In this study, we provide the first identification and characterization of an l-2,3-BD dehydrogenase from K. pneumoniae, demonstrating its reductive activities toward diacetyl and acetoin, and oxidative activity toward l-2,3-BD. Optimum pH, temperature, and kinetics determined for reductive and oxidative reactions support the preferential production of 2,3-BD during cell growth. Synthesis of l-2,3-BD was remarkably enhanced by increasing gene dosage, reaching levels that, to the best of our knowledge, are the highest achieved to date.     

Effects of Dietary Zinc and l-Arginine Supplementation on Total Antioxidants Capacity, Lipid Peroxidation, Nitric Oxide, Egg Weight, and Blood Biochemical Values in Japanase Quails

The aim of this study was to evaluate effects of dietary zinc and l-arginine supplementation on blood total antioxidant capacity (TAC), malondialdehyde (MDA), nitric oxide (NO), some blood chemistry parameters, and egg weights of laying quails. Three groups of Japanese quails were fed with a diet containing l-arginine (5 mg/kg), zinc (60 mg/kg), and normal basal diet (control) for 30 days. TAC, lipid peroxidation, and biochemical analysis were performed in the blood of animals. l-Arginine and zinc supplementation improved TAC and reduced MDA concentrations compared to the control (P?<?0.05). In comparison to the control, blood NO concentrations were increased by l-arginine (P?<?0.01) and zinc treatment (P?<?0.05). Both zinc (P?<?0.001) and l-arginine (P?<?0.01) supplementation significantly increased egg weight in laying quails. Some of the blood chemistry parameters were also altered by the treatment of l-arginine and zinc supplementation. No difference was found in blood albumin and creatinine levels among the groups. Blood glucose (P?=?0.833) and total protein (P?=?0.264) levels in control and l-arginine-treated groups were found to be similar. Glucose and total protein levels were decreased in zinc-supplemented animals compared to the control and l-arginine groups (P?<?0.05). No difference was found in triglyceride levels between control and zinc-applied groups (P?=?0.197). However, l-arginine treatment reduced the blood triglyceride levels compared to the control (P?<?0.05). In conclusion, l-arginine and zinc supplementation could be beneficial and effective for decreasing oxidative stress, boosting antioxidant capacity, and improving egg weight in the blood of the animals.     

Comparison of N-Methyl-d-aspartate Receptor Subunit 1 and 4-Hydroxynonenal in the Hippocampus of Natural and Chemical-Induced Aging Accelerated Mice

In this study, we compared N-methyl-d-aspartate receptor type 1 (NMDAR1) and 4-hydroxynonenal (4-HNE) in the hippocampus of d-galactose (d-gal)-induced and naturally aging models of mice. These markers represent general phenotypes in aging, and they allowed us to examine the possibility of d-gal as a chemical model agent for aging. We observed an age-dependent reduction of NMDAR1 and an increase in 4-HNE in the dentate gyrus, CA1, and CA3 regions of the hippocampus via immunohistochemistry and western blot analyses. In the d-gal-induced chemical aging model, we observed similar changes in NMDAR1 and 4-HNE although the degree of reduction/increase in NMDAR1/4-HNE was not as severe as that in the naturally aged mice. These results suggest that the d-gal-induced aging model is comparable to naturally aged mice and may be useful for studies of the aging hippocampus.     

Determination and stereochemistry of proteinogenic and non-proteinogenic amino acids in Saudi Arabian date fruits

Whereas an abundance of literature is available on the occurrence of common proteinogenic amino acids (AAs) in edible fruits of the date palm (Phoenix dactylifera L.), recent reports on non-proteinogenic (non-coded) AAs and amino components are scarce. With emphasis on these components we have analyzed total hydrolysates of twelve cultivars of date fruits using automated ion-exchange chromatography, HPLC employing a fluorescent aminoquinolyl label, and GC–MS of total hydrolysates using the chiral stationary phases Chirasil^®-L-Val and Lipodex^® E. Besides common proteinogenic AAs, relatively large amounts of the following non-proteinogenic amino acids were detected: (2S,5R)-5-hydroxypipecolic acid (1.4–4.0 g/kg dry matter, DM), 1-aminocyclopropane-1-carboxylic acid (1.3–2.6 g/kg DM), γ-amino-n-butyric acid (0.5–1.2 g/kg DM), (2S,4R)-4-hydroxyproline (130–230 mg/kg DM), l-pipecolic acid (40–140 mg/kg DM), and 2-aminoethanol (40–160 mg/kg DM) as well as low or trace amounts (<70 mg/kg DM) of l-ornithine, 5-hydroxylysine, β-alanine, and in some samples (<20 mg/kg DM) of (S)-β-aminoisobutyric acid and (<10 mg/kg DM) l-allo-isoleucine. In one date fruit, traces of α-aminoadipic acid could be determined. Enantiomeric analysis of 6 M DCl/D₂O hydrolysates of AAs using chiral capillary gas chromatography–mass spectrometry revealed the presence of very low amounts of d-Ala, d-Asp, d-Glu, d-Ser and d-Phe (1.2–0.4 %, relative to the corresponding l-enantiomers), besides traces (0.2–1 %) of other d-AAs. The possible relevance of non-proteinogenic amino acids in date fruits is briefly addressed.     

Biotransformation of l-ornithine from l-arginine using whole-cell recombinant arginase

A recombinant arginase was generated for a whole-cell biotransformation system to convert l-arginine to l-ornithine in Escherichia coli. The gene ARG1 coding arginase from Bos taurus liver was synthesized and expressed in E. coli BL21 (DE3) via pETDuet-1. The recombinant arginase was used to catalyze l-arginine to l-ornithine and urea. The reaction was optimal at pH 9.5 and 37 °C. Manganese (10^?5 M) and Emulsifier OP-10 [0.033 % (v/v)] could promote arginase activity. In a scale up study, l-arginine conversion rate reached 98 % with a final concentration of 111.52 g l-ornithine/l.     

Arginine increases genotoxicity induced by methyl methanesulfonate in human lymphocytes

Nitric oxide (NO) is a free radical that is produced in cells from l-arginine. NO is involved in the physiological control of different tissues, but it can act as a toxic mediator in the cells. In this study we investigated the effect of l-arginine on the genotoxicity induced by methyl methanesulfonate (MMS) in human lymphocytes. Blood was treated with N^G-nitro-l-arginine methyl ester (l-NAME) as an inhibitor of nitric oxide synthase for finding out the role of NO in this effect. Human whole blood was treated with l-arginine (50, 100 and 250 μM) and/or l-NAME, then it was treated in vitro with MMS after 24 h of culture. The lymphocytes were stimulated by phytohemagglutinin to find out the micronuclei in cytokinesis-blocked binucleated cells. DNA fragmentation of lymphocytes was detected by using a fluorescence microscope after propidium iodide staining. These data showed that arginine increased the frequency of MMS-induced micronuclei in lymphocytes. However, the genotoxicity was decreased by using l-NAME. Arginine and l-NAME have not shown any DNA damage in cultured human lymphocytes. In conclusion, addition of l-arginine to MMS as an alkylating agent caused an increase of DNA damage in human lymphocytes. This enhancement of genotoxicity was reduced by NAME as NO inhibitor. It is thus cleared that an increase of DNA damage by arginine and MMS is related to NO production.     

Involvement of Neurotransmitters in the Action of the Nociceptin/Orphanin FQ Peptide-Receptor System on Passive Avoidance Learning in Rats

The nociceptin/orphanin FQ peptide (NOP) receptor and its endogenous ligand plays role in several physiologic functions of the central nervous system, including pain, locomotion, anxiety and depression, reward and drug addiction, learning and memory. Previous studies demonstrated that the NOP-receptor system induces impairment in memory and learning. However, we have little evidence about the underlying neuromodulation. The aim of the present study was to investigate the involvement of distinct neurotransmitters in the action of the selective NOP receptor agonist orphan G protein-coupled receptor (GPCR) SP9155 P550 on memory consolidation in a passive avoidance learning test in rats. Accordingly, rats were pretreated with a nonselective muscarinic acetylcholine receptor antagonist, atropine, a γ-aminobutyric acid subunit A (GABA-A) receptor antagonist, bicuculline, a D2, D3, D4 dopamine receptor antagonist, haloperidol, a nonselective opioid receptor antagonist, naloxone, a non-specific nitric oxide synthase inhibitor, nitro-l-arginine, a nonselective α-adrenergic receptor antagonist, phenoxybenzamine and a β-adrenergic receptor antagonist, propranolol. Atropine, bicuculline, naloxone and phenoxybenzamine reversed the orphan GPCR SP9155 P550-induced memory impairment, whereas propranolol, haloperidol and nitro-l-arginine were ineffective. Our results suggest that the NOP system-induced impairment of memory consolidation is mediated through muscarinic cholinergic, GABA-A-ergic, opioid and α-adrenergic receptors, whereas β-adrenergic, D2, D3, D4-dopaminergic and nitrergic mechanisms are not be implicated.     

Anti-apoptosis effect of polysaccharide isolated from the seeds of Cuscuta chinensis Lam on cardiomyocytes in aging rats

To investigate the mechanism of apoptosis in myocardial cells of aging rats induced by d-galactose and to study the effect of the Polysaccharide isolated from the seeds of Cuscuta chinensis Lam (PCCL) on apoptosis of cardiomyocytes and its corresponding machinasim in aging rat model. Fifty male SD rats were randomly divided into 5 groups. Normal control group (NC). d-galactose (100 mg·kg^?1d^?1 for 56 day) indued aging group (MC), d-galactose plus 100 mg kg^?1 d^?1 PCCL group (ML), d-galactose plus 200 mg kg^?1 d^?1 PCCL group (MM), and d-galactose plus 400 mg kg^?1 d^?1 PCCL group (MH). Same volume of solution (water, or PCCL aqueous solution) was given by gavage for 56 days. Then the hearts were collected and apoptosis parameters were evaluated. Caspase-3 and Cyt c were determined by fluorescence spectrometer, the apoptosis rate was assessed by AnnexinV-FITC method by Flow-Cytometry, [Ca²⁺]i and [Ca²⁺]i overloaded by KCL were observed by laser scanning confocal microscopy (LSCM); Bcl-2 and Bax were examined by immunohistochemistry. The content of Cyt C, [Ca²⁺]i of cardiomyocytes, the activity of Caspase-3, Bax expression level in d-galactose induced aging group were higher than NC (p < 0.05). The ratio of Bcl-2/Bax was decreased in d-galactose induced aging group compared to NC. On the other hand, the content of Cyt C, [Ca²⁺]i of cardiomyocytes, the activity of Caspase-3 and apoptosis rate, as well as Bax expression level in all three PCCL groups were decreased compared to galactose induced group (p < 0.05). Bcl-2/Bax ratio was increased in all PCCL groups compared to galactose induced aging group. PCCL could decrease the apoptosis of cardiomyocytes by the mitochondria apoptosis pathway.     

The Effects of l-Arginine, Alone and Combined with Vitamin C, on Mineral Status in Relation to its Antidiabetic, Anti-Inflammatory, and Antioxidant Properties in Male Rats on a High-Fat Diet

The aim of this study was to evaluate the influence of the intake of l-arginine alone and of l-arginine with vitamin C on mineral concentration in rats fed with a high-fat diet, and to assess the lipid glucose, insulin, and total antioxidant status (TAS) and tumor necrosis factor (TNF) alpha serum levels that result. Wistar rats were assigned to groups fed with either a standard control diet (C), a diet high in fat (FD), a diet high in fat with l-arginine, or a diet high in fat with l-arginine and vitamin C. After 6 weeks, the length and weight of the rats were measured, and the animals were euthanized. The liver, spleen, kidneys, pancreas, heart, and gonads were collected, as were blood samples. The total serum cholesterol, triglyceride, fasting glucose, insulin, TAS, and TNF alpha levels were measured. The tissue calcium, magnesium, iron, zinc, and copper concentrations were determined. It was found that l-arginine supplementation diminished the effect of the modified diet on the concentration of iron in the liver and spleen and of copper in heart. At the same time, it was observed that l-arginine supplementation reduced the effect of the high-fat diet on insulin, TNF alpha, and TAS. The combination of l-arginine and vitamin C produced a similar effect on the mineral levels in the tissues as did l-arginine used alone. Moreover, positive correlations between serum insulin and iron in the liver, between TNF alpha and iron in the liver, and between TNF alpha and copper in the heart were observed. The level of TAS in serum was inversely correlated with the copper level in the heart and the iron level in the liver. We concluded that the beneficial influence of l-arginine on insulin, TAS, and TNF alpha serum level is associated with changes in the iron and copper status in rats fed with a high-fat diet. No synergistic effect of l-arginine and vitamin C in the biochemical parameters or in the mineral status in rats fed with the modified diet was observed.     

Basic amino acids and dimethylarginines targeted metabolomics discriminates primary hepatocarcinoma from hepatic colorectal metastases

Hepatocellular carcinoma (HCC) is a very aggressive neoplasia requiring early and accurate diagnosis to improve patient outcomes with timely treatment. The liver is also very frequently colonized by metastases, and the most frequent differential diagnosis is HCC against intrahepatic cholangiocarcinoma or metastatic adenocarcinoma. Metabolomics is a powerful tool for identification of altered biomarkers in cancer, and to evaluate the efficacy of drug treatments. Here we analyzed by HILIC-MS/MS methylated arginines, basic amino acids (Arg, Cit, Orn), and their ratios in the extracts of primary HCC tissues, liver metastases from colorectal carcinoma (MET), cirrhotic related hepatitis-C-virus (CIR), and non-cirrhotic normal liver (NT) adjacent tissues. We found high levels of Arg (p < 0.0001) and Arg/Orn (p < 0.01) in MET compared to other tissues. In MET, compared to NT and CIR, Arg concentration was fivefold higher, while in HCC it was twofold higher. ADMA increased twofold compared to NT and CIR, while in HCC it was 50 % higher. Arg/Cit and ADMA/SDMA ratios were significantly higher in MET compared to NT and CIR (p < 0.005). Arg/Orn, Arg/Cit, and ADMA/SDMA ratios increased progressively from NT, CIR, HCC, to MET tissues. Arg/Cit correlated significantly with Arg/Orn ratios (r = 0.77; p < 0.0001), and discriminates tumor from non-tumor samples. In addition, the discriminant lactate/glucose ratio we previously found by NMR, also correlated significantly with the Arg levels (r = 0.64; p < 0.0001), and discriminated MET from all other tissues. The results indicated that Arg in MET is higher than other tissue classes, suggesting that, together with the lactate/glucose ratio, it can be considered a further biomarker for HCC-metastases differentiation.     

Effects of exogenous l-arginine on in vitro rooting, chlorophyll, carbohydrate, and proline concentrations in the sweet cherry rootstock M × M 14 (Prunus avium L. × Prunus mahaleb L.)

The effects of indole-3-butyric acid (IBA) alone and in combination with l-arginine on the morphogenic and biochemical responses in shoot tip explants of the cherry rootstock M × M 14 (Prunus avium × Prunus mahaleb) were examined. The maximum root number per rooted explant (16), root fresh (FW) and dry (DW) weights, as well as the rooting percentage (100 %) were recorded when 2 mg l^?1 IBA (alone) were applied. Including the lowest IBA concentration (0.5 mg l^?1) with the lowest and highest l-arginine concentrations (0.5 and 2 mg l^?1, respectively) resulted in the greatest root length. The maximum leaf chlorophyll concentration and shoot length of the initial explant were recorded when 0.5 mg l^?1 IBA plus 2 mg l^?1 l-arginine were applied. In addition, l-arginine in combination with IBA (1 and 2 mg l^?1) was found to suppress shoot FW and DW. On the other hand, l-arginine enhanced the promoting effect of IBA on both root length and leaf chlorophyll concentration. The carbohydrate and proline concentrations in leaves were not significantly altered with the application of IBA alone or in combination with l-arginine. On the other hand, the carbohydrate and proline concentrations in roots were decreased with the application of 1 and 2 mg l^?1 IBA with l-arginine, resulting in the suppression of the promoting effects of IBA. It is clear from the findings that l-arginine has a direct effect on the in vitro rooting of M × M 14 explants, is involved in the function of the photosythetic apparatus, influences leaf chlorophyll content, participates in carbohydrate biosynthesis and metabolism, and is involved in proline accumulation both in leaves and roots.     

Polyamines and Nitric Oxide Link in Regulation of Dormancy Removal and Germination of Apple (Malus domestica Borkh.) Embryos

Polyamines (PAs) belong to plant growth regulators and in complex with classical phytohormones take part in regulation of seed dormancy and germination. Although the impact of reactive oxygen (ROS) and nitrogen (RNS) species on seed germination is well described, the cross talk of PAs with ROS/RNS has never been analyzed. Due to the close connection of PAs and ethylene biosynthetic pathways to arginine (Arg)-dependent NO biosynthesis we investigated production of nitric oxide (NO), peroxynitrite (ONOO^?) and the level of O ₂ ^?? or H₂O₂ in apple embryos, germination of which was PA regulated. PAs: putrescine (Put) and spermidine (Spd) in contrast to spermine (Spm) stimulated germination of apple embryos. Among amino acids, stimulation of germination was observed in Arg and ornithine (Orn) only. Dormancy removal of embryos by PAs was associated with increased accumulation of H₂O₂ and O ₂ ^?? in embryonic axes. At the same stage of completion of sensu stricto germination the stimulatory effect of PAs (Put and Spd) and amino acids, mainly Arg and Orn, was accompanied by enhanced NO and ONOO^? production in embryonic axis. The beneficial effect of PAs (Put and Spd) and their precursors on germination of apple embryos was removed by NO scavenging, suggesting a crucial role of NO in termination of embryo germination and radicle growth. Moreover, activity of polyamine oxidase in embryo axes was greatly enhanced by embryo fumigation with NO. Our data demonstrate the interplay of RNS/ROS with PAs and point to NO action as an integrator of endogenous signals activating germination.     

Beneficial effects of l-arginine on reducing obesity: potential mechanisms and important implications for human health

Over the past 20 years, growing interest in the biochemistry, nutrition, and pharmacology of l-arginine has led to extensive studies to explore its nutritional and therapeutic roles in treating and preventing human metabolic disorders. Emerging evidence shows that dietary l-arginine supplementation reduces adiposity in genetically obese rats, diet-induced obese rats, finishing pigs, and obese human subjects with Type-2 diabetes mellitus. The mechanisms responsible for the beneficial effects of l-arginine are likely complex, but ultimately involve altering the balance of energy intake and expenditure in favor of fat loss or reduced growth of white adipose tissue. Recent studies indicate that l-arginine supplementation stimulates mitochondrial biogenesis and brown adipose tissue development possibly through the enhanced synthesis of cell-signaling molecules (e.g., nitric oxide, carbon monoxide, polyamines, cGMP, and cAMP) as well as the increased expression of genes that promote whole-body oxidation of energy substrates (e.g., glucose and fatty acids) Thus, l-arginine holds great promise as a safe and cost-effective nutrient to reduce adiposity, increase muscle mass, and improve the metabolic profile in animals and humans.     

Low Energy Conformations for Gonadotropin-Releasing Hormone with d- and l-Amino Acid Substitutions for Gly 6: Possible Receptor-Bound Conformations

In the preceding paper, using ECEPP, including the effects of water, and the chain build-up procedure, we computed the low energy structures for GnRH and found that there were no distinct low energy structures or structures with high statistical weights. To attempt to deduce possible structures of GnRH that may bind to the GnRH receptor, we computed the low energy structures for GnRH peptides that have l- and d-amino acids substituting for Gly 6. The l-amino acid-substituted peptides (l-Ala and l-Val) have very low or no affinity for the receptor and on activity (release of FSH and LH) while the d-Ala-, d-Leu-, d-Trp- and d-Phe-substituted peptides have significantly higher relative affinities and activities than those for native GnRH; the d-Val-substituted peptide has about one-third of the affinity and activity as native GnRH. Unlike native GnRH, our computations suggest that both sets of peptides form well-defined structures in water: the l-amino acid-substituted peptides are predominantly α-helical while the d-amino acid-substituted peptides adopted E*A A A E D*(C*) A E C A(C*) and minor variants of these structures. By eliminating structures that lay in common to the d-Ala and l-Val peptides and further eliminating structures that differed between the d-Ala and d-Leu peptides, we reduced the number of possible distinct binding conformations to 254. Searching for structures among these 254 conformations that had relative statistical weights that paralleled their relative affinities, we found two candidate structures: D*E A A E C*A E C A and D*G A A E D*A E C G*, both of which have conformations for residues 3–9 that are similar to the computed most probable structures for the d-amino acid-substituted GnRH peptides in water.     

Vibrio madracius sp. nov. Isolated from Madracis decactis (Scleractinia) in St Peter & St Paul Archipelago,Mid-Atlantic Ridge,Brazil

Three novel isolates (A-354^T, A-328, and A-384) were retrieved from apparently healthy scleractinian Madracis decactis in the remote St Peter & St Paul Archipelago, Mid-Atlantic Ridge, Brazil. The novel isolates formed a distinct lineage based on the phylogenetic reconstruction using the 16S rRNA and pyrH gene sequences. They fell into the Mediterranei clade and their closest phylogenetic neighbour was V. mediterranei species, sharing upto 98.1 % 16S rRNA gene sequence similarity. Genomic analysis including in silico DDH, MLSA, AAI and genomic signature distinguished A-354^T from V. mediterranei LMG 19703 (=AK1) with values of 33.3, 94.2, 92 %, and 11.3, respectively. Phenotypically, the novel isolates can be differentiated from V. mediterranei based on the four following features. They do not grow at 8 % NaCl; use d-gluconic acid but not l-galactonic acid lactone as carbon source; and do not have the fatty acid C_18:0. Differentiation from both the other Mediterranei clade species (V. maritimus and V. variabilis) is supported by fifteen features. The novel species show lysine decarboxylase and tryptophan deaminase, but not gelatinase and arginine dihydrolase activity; produce acetoin; use α-d-lactose, N-acetyl-d-galactosamine, myo-Inositol, d-gluconic acid, and β-hydroxy-d,l-butyric acid; and present the fatty acids C_14:0 iso, C_15:0 anteiso, C_16:0 iso, C_17:0 anteiso, and C_17:1x8c . Whole-cell protein profiles, based on MALDI-TOF, showed that the isolates are not clonal and also distinguished them from the closes phylogenetic neighbors. The name Vibrio madracius sp. nov. is proposed to encompass these novel isolates. The G+C content of the type strain A-354^T (=LMG 28124^T=CBAS 482^T) is 44.5 mol%.