Isolation of a new antibacterial peptide actinokineosin from Actinokineospora spheciospongiae based on genome mining.

Based on genome mining, a new antibacterial peptide named actinokineosin was isolated from a rare actinomycete Actinokineospora spheciospongiae. The amino acid sequence of the C-terminus of actinokineosin was established by TOF-MS/MS experiments. The amino acid sequence in the macrolactam ring was determined by TOF-MS/MS analyses after cleavage with BNPS-skatole and successive trypsin treatment. As a result of an antibacterial assay using a paper disk, actinokineosin showed antibacterial activity against Micrococcus luteus at a dosage of 50 µg per disk. From the genome sequence data of A. spheciospongiae, the biosynthetic gene cluster of actinokineosin was found and was indicated to consist of 10 genes. Among the genes, the gene aknA encoded the precursor of actinokineosin and the genes including aknC, aknB1 and aknB2 were proposed as modification enzymes to give mature actinokineosin. SIGNIFICANCE AND IMPACT OF THE STUDY: Genome mining is a powerful tool to find new bioactive compounds from the genome database. In this report, we succeeded in isolation and structure determination of a new antibacterial peptide named actinokineosin based on genome mining.

Evidence for biological nitrification inhibition in Brachiaria pastures.

Nitrification, a key process in the global nitrogen cycle that generates nitrate through microbial activity, may enhance losses of fertilizer nitrogen by leaching and denitrification. Certain plants can suppress soil-nitrification by releasing inhibitors from roots, a phenomenon termed biological nitrification inhibition (BNI). Here, we report the discovery of an effective nitrification inhibitor in the root-exudates of the tropical forage grass Brachiaria humidicola (Rendle) Schweick. Named "brachialactone," this inhibitor is a recently discovered cyclic diterpene with a unique 5-8-5-membered ring system and a gamma-lactone ring. It contributed 60-90% of the inhibitory activity released from the roots of this tropical grass. Unlike nitrapyrin (a synthetic nitrification inhibitor), which affects only the ammonia monooxygenase (AMO) pathway, brachialactone appears to block both AMO and hydroxylamine oxidoreductase enzymatic pathways in Nitrosomonas. Release of this inhibitor is a regulated plant function, triggered and sustained by the availability of ammonium (NH(4)(+)) in the root environment. Brachialactone release is restricted to those roots that are directly exposed to NH(4)(+). Within 3 years of establishment, Brachiaria pastures have suppressed soil nitrifier populations (determined as amoA genes; ammonia-oxidizing bacteria and ammonia-oxidizing archaea), along with nitrification and nitrous oxide emissions. These findings provide direct evidence for the existence and active regulation of a nitrification inhibitor (or inhibitors) release from tropical pasture root systems. Exploiting the BNI function could become a powerful strategy toward the development of low-nitrifying agronomic systems, benefiting both agriculture and the environment.

Minimum stable structure of the receptor for advanced glycation end product possesses multi ligand binding ability.

The receptor for advanced glycation end products (RAGE) is a multi-ligand receptor involved in the development of diabetic complications. Although the soluble form of the extracellular domain maintains the ability to bind multi-ligands, it is unstable and degrades into several peptide species during storage. Proteolysis with thrombin or factor Xa revealed several protease sensitive sites. Most sensitive site is located between Arg228 and Val229, and peptide bond next to Arg216, Arg116, Arg114 and Trp271 are also cleaved. Seven truncated extracellular domains of RAGE were engineered in order to obtain a stable soluble fragment. RAGE 143 (Ala23-Thr143) is not only protease resistant but also shows the same ligand-binding ability as that of the full-length extracellular domain. The resultant minimum RAGE 143 works as a stable recognition devise to detect advanced glycation end products (AGEs).

Differential expression of the skeletal muscle proteome in grazed cattle.

The objective of this study was to investigate the differences in the muscle proteome of grass-fed and grain-fed cattle. Eight Japanese Black Cattle 10 mo of age were separated randomly into 2 groups: 1) grazing (grass-fed) and 2) concentrate (grain-fed) groups. All cattle were first housed individually in a stall barn and fed a combination of concentrate ad libitum and Italian ryegrass hay until 21 mo of age. After this control period, the 4 grass-fed cattle were placed on outdoor pasture, whereas the other 4 grain-fed cattle continued on the concentrate diet. The cattle were slaughtered at 27 mo of age, and tissues from the semitendinosus muscle were obtained for use in proteome analysis. Differential expression of muscle proteins in the 2 groups was carried out using 2-dimensional gel electrophoresis (2DE) and Western blot analyses, with subsequent mass spectrometry. Approximately 200 individual protein spots were detected and compared in each group using 2DE, of which 20 and 9 spots, respectively, showed differences in the spot intensity for the sarcoplasmic fraction and myofibrillar fraction. In the grazing group, the relative intensity of spots was significantly greater for adenylate kinase 1 and myoglobin in the sarcoplasmic fraction, and for slow-twitch myosin light chain 2 in the myofibrillar fraction (P < 0.05), than the concentrate group. The relative spot intensity of several glycolytic enzymes was significantly greater in the grazing group, such as beta-enolase 3, fructose-1,6-bisphosphate aldolase A, triosephosphate isomerase, and heat shock 27 kDa protein (P < 0.05). Moreover, significantly greater slow twitch of troponin T, troponin I, and myosin heavy chain of semitendinosus muscle was detected in the grazing group than in the concentrate group using Western blot analysis (P < 0.05). Several previous reports have described that the slow-twitch muscle contents affect elements of nutrition, flavor, and food texture of meat. This study revealed muscle fiber type conversion to slow-twitch tissues from fast-twitch tissues occurring with change in the energy metabolic enzyme when cattle were grazed in the latter fattening period. Although analyses of the influence on elements of nutrition, flavor, and food texture were not done for this study, these results show that slow-twitch converted muscle resulting from the grazing of cattle might modify several meat characteristics.

Ergosterol peroxide from an edible mushroom suppresses inflammatory responses in RAW264.7 macrophages and growth of HT29 colon adenocarcinoma cells.

BACKGROUND AND PURPOSE: 5alpha,8alpha-Epidioxy-22E-ergosta-6, 22-dien-3beta-ol (ergosterol peroxide) is a major antitumour sterol produced by edible or medicinal mushrooms. However, its molecular mechanism of action has yet to be determined. Here, we examine the anticancer and anti-inflammatory effects of ergosterol peroxide. EXPERIMENTAL APPROACH: After treating RAW264.7 macrophages with LPS and purified ergosterol peroxide or ergosterol, we determined LPS-induced inflammatory cytokines, nuclear DNA binding activity of transcription factors and phosphorylation of MAP kinases (MAPKs). HT29 colorectal adenocarcinoma cells were treated with ergosterol peroxide for 5 days. To investigate the antitumour properties of ergosterol peroxide, we performed DNA microarray and RT-PCR analyses and determined the reactive oxygen species (ROS) in HT29 cells. KEY RESULTS: Ergosterol peroxide suppressed LPS-induced TNF-alpha secretion and IL-1alpha/beta expression in RAW264.7 cells. Ergosterol peroxide and ergosterol suppressed LPS-induced DNA binding activity of NF-kappaB and C/EBPbeta, and inhibited the phosphorylation of p38, JNK and ERK MAPKs. Ergosterol peroxide down-regulated the expression of low-density lipoprotein receptor (LDLR) regulated by C/EBP, and HMG-CoA reductase (HMGCR) in RAW264.7 cells. In addition, ergosterol peroxide showed cytostatic effects on HT29 cells and increased intracellular ROS. Furthermore, ergosterol peroxide induced the expression of oxidative stress-inducible genes, and the cyclin-dependent kinase inhibitor CDKN1A, and suppressed STAT1 and interferon-inducible genes. CONCLUSION AND IMPLICATION: Our results suggest that ergosterol peroxide and ergosterol suppress LPS-induced inflammatory responses through inhibition of NF-kappaB and C/EBPbeta transcriptional activity, and phosphorylation of MAPKs. Moreover, ergosterol peroxide appears to suppress cell growth and STAT1 mediated inflammatory responses by altering the redox state in HT29 cells.

Muscle type specific expression of tropomyosin isoforms in bovine skeletal muscles.

Nucleotide sequences encoding an entire coding region for bovine tropomyosin (TPM) isoforms were determined. Three TPM isoforms, TPM1, TPM2 and TPM3, were expressed in bovine skeletal muscles, and exhibited a 93.3%, 99.6% and 100% amino acid homology to the human sequence, respectively. Based on the sequences, the composition of TPM isoforms was analyzed on cDNA and protein levels from five physiologically different muscles (masseter, diaphragm, psoas major, longissimus thoracis and semitendinosus) using RT-PCR and proteome analyses. Although the content of TPM2 was constantly about 50% of the total TPM in all muscles, the contents of TPM1 and TPM3 were different in muscles according to their function in muscle contraction. In masseter, the content of TPM3 cDNA was about 50% and higher than that of other muscles. In longissimus thoracis and semitendinosus, the contents of TPM1 cDNA were 29.6% and 31.7%, respectively, which were comparatively higher than that of other muscles. The result suggests that the TPM dimer consists of the TPM2 subunit regularly and TPM1 or TPM3 depending on whether the muscle is fast or slow type, respectively.

Analysis of acrylamide by LC-MS/MS and GC-MS in processed Japanese foods.

Acrylamide concentrations in processed foods (63 samples covering 31 product types) from Japan were analysed by LC-MS/MS and GC-MS methods. The limit of detection and limit of quantification of acrylamide were 0.2 ng x ml(-1) (6 fmol) and 0.8 ng x ml(-1) (22 fmol), respectively, by LC-MS/MS, and those of 2,3-dibromopropionamide derived from acrylamide were 12 ng x ml(-1) (52 fmol) and 40 ng x ml(-1) (170 fmol), respectively, by GC-MS. Repeatability given as RSD was <5 and <15% for the LC-MS/MS and GC-MS methods, respectively. High correlation (r(2) - 0.946) was observed between values obtained by the two methods. Most potato crisps and whole potato-based fried snacks showed acrylamide concentrations >1000 microg x kg(-1). The concentrations in non-whole potato-based snacks, rice crackers processed by grilling or frying, and candied sweet potatoes were lower compared with those in the potato crisps and the whole potato-based fried snacks. One of the whole potato-based fried snacks, however, showed low acrylamide concentration (<50 microg x kg(-1)) suggesting the formation of acrylamide is strongly influenced by processing conditions. Acrylamide concentrations in instant precooked noodles and won-tons were <100 microg x kg(-1) with only one exception. Roasted barley grains for 'Mugi-cha' tea contained 200-600 microg x kg(-1) acrylamide.

Highly polymerized procyanidins in brown soybean seed coat with a high radical-scavenging activity.

1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity of the 70% aqueous acetone extract from the seed coat of the brown soybean variety, Akita-Zairai, was investigated. The activity of the seed coat of Akita-Zairai was much higher than that of three other reddish-brown varieties, but lower than that of two black varieties, and was closely dependent on the content of phenolic compounds. In the LH20 column chromatography of Akita-Zairai, high DPPH radical-scavenging activities were detected in the fractions eluted with MeOH and 70% aqueous acetone. Proanthocyanidins were also detected in fractions showing high radical-scavenging activities. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry analysis showed that the degree of polymerization (DP) of the procyanidins contained in the brown or black soybean seed coat was as high as DP30.

Acylated anthocyanidin 3-sophoroside-5-glucosides from Ajuga reptans flowers and the corresponding cell cultures.

Four anthocyanins from Ajuga reptans flowers and its cell cultures were isolated, and a fifth was also characterized by HPLC-mass spectrometry. By means of chemical and spectroscopic analyses, their structures were identified as delphinidin 3-(p-coumaroyl-feruloyl)sophoroside-5-malonylglucoside, delphinidin 3-(diferuloyl)sophoroside-5-malonylglucoside, and cyanidin 3-(di-p-coumaroyl)sophoroside-5-glucoside, respectively. The other two were tentatively identified as delphinidin 3-(diferuloyl)sophoroside-5-glucoside and cyanidin 3-(feruloyl-p-coumaroyl)sophoroside-5-malonylglucoside. In neutral aqueous solution, the crude extract from A. reptans flower cell cultures and the major anthocyanin cyanidin 3-(di-p-coumaroyl)sophoroside-5-malonylglucoside were more stable than cyanidin 3-glucoside, and also prevented more efficiently peroxidation than did the latter. A. reptans flower cell culture anthocyanins may have a potential as natural colorants for food utilities or other purposes.

Binding of barley and wheat alpha-thionins to polysaccharides.

An antimicrobial peptide termed BCP-2 was purified from barley grain by chitin-affinity treatment and HPLC. The results of amino acid analysis and mass spectrometry of BCP-2 indicate that the peptide is very similar to barley alpha-thionin. BCP-2 and wheat alpha1-thionin were also bound to beta-glucan but not to starch. The binding of BCP-2 to laminarin (beta-1,3-1,6-glucan) and laminarioligosaccharides was supported by fluorescence polarization data. This is the first report on the binding of alpha-thionins to polysaccharide containing chitin and beta-1,3-glucan, which construct fungal cell walls.

A lectin from an edible mushroom Pleurotus ostreatus as a food intake-suppressing substance.

In an experiment in which rats were allowed free access to food and water, the rats did not eat the diet containing a mushroom Pleurotus ostreatus even if they were emaciated. A P. ostreatus lectin (POL) was isolated from the mushroom as the food intake-suppression principle. In hemagglutination inhibition assays, Me-alphaGalNAc was the most potent inhibitor among the monosaccharides tested. Among all the sugars tested, 2'-fucosyllactose (Fucalpha1-->2Galbeta1-->4Glc) was the strongest inhibitor and its inhibitory potency was five times greater than that of Me-alphaGalNAc. POL exhibited a binding ability to bovine submaxillary mucin (BSM) and asialo-BSM and the other glycoproteins were inert to the binding. The food intake-suppressing activity of POL was dependent on the dose. The diet containing 0.1% POL caused a 50% decrease in the food intake of rats against the control.

Two novel diterpenoids, erinacines H and I from the mycelia of Hericium erinaceum.

Novel diterpenoids, erinacines H (1) and I (3), were isolated from the cultured mycelia of Hericium erinaceum. The structures of the compounds were determined by interpretation of the spectral data. Erinacine H showed stimulating activity of nerve growth factor (NGF)-synthesis.

Extraction and identification of antioxidants in the roots of yacon (Smallanthus sonchifolius).

Yacon, Smallanthus sonchifolius (Poepp. & Endl.) H. Robinson, Asteraceae, an important economic species grown for its juicy tuberous root, is potentially beneficial in the diet to diabetics. The antioxidative activity of yacon root was studied by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay. Antioxidants were extracted by methanol and isolated and purified by gel permeation chromatography and preparative reverse-phase HPLC. Two of the major antioxidants were identified as chlorogenic acid and tryptophan by NMR and mass spectrometry.

Mumefural, citric acid derivative improving blood fluidity from fruit-juice concentrate of Japanese apricot (Prunus mume Sieb. et Zucc).

The effects of food components on blood fluidity were studied by in vitro assay using a dedicated microchannel instrument for model capillaries. We found that the fruit-juice concentrate of the Japanese apricot (Prunus mume Sieb. et Zucc), a traditional Japanese food, markedly improved the fluidity of human blood. Using HPLC, we isolated the active compounds and characterized them using UV, MS, IR, and NMR. They included a novel compound, 1-[5-(2-formylfuryl)methyl] dihydrogen 2-hydroxypropane-1,2, 3-tricarboxylate (mumefural), and a related compound, 5-hydroxymethyl-2-furfural (HMF). Mumefural markedly improved blood fluidity in all subjects, while HMF worked differently in different individuals. The flow rate of blood spiked with mumefural or HMF was compared to that of the two predominant organic acids in the fruit. Citric acid, malic acid, and furfuryl alcohol also improved fluidity in all subjects. The activity of P. mume is derived from not only artifacts produced during thermal processing, such as mumefural, but also from endogenous organic acids.

Cloning and expression of chitin deacetylase gene from a Deuteromycete, Colletotrichum lindemuthianum.

The chitin deacetylase gene was cloned from cDNA of Colletotrichum lindemuthianum ATCC 56676, and the open reading frame consisted of a possible prepro-sequence of 27 amino acids at the N-terminus and a mature chitin deacetylase. The deduced amino acid sequence of the mature enzyme revealed 26% identity and 46% similarity with a chitin deacetylase from Mucor rouxii. The molecular mass of the protein estimated from the amino acid sequence data was 24.3 kDa, which was in good agreement with the MALDI-TOF MS analysis data of the purified protein (24.17-24.36 kDa). The gene product was overexpressed in Escherichia coli cells as a fusion protein with six histidine residues at its C-terminus. The fusion protein formed inclusion bodies, but chitin deacetylase activity was restored from the inclusion bodies by a simple renaturation step with 8 M urea treatment. The recombinant enzyme was purified by affinity chromatography and gel filtration steps, and had a final specific activity of 4.22 units mg(-1) of protein. Trypsin digestion of the recombinant enzyme resulted in 2.1-fold increase in activity, suggesting that the removal of the prepro-domain from the recombinant enzyme resulted in an increase in its activity.

An Application of X-ray Fluorescence Spectrometry to the Study of Thin-Layer Chromatography.

The combination of thin-layer chromatography (TLC) with X-ray fluorescence spectrometry (XRF) has been accomplished without any interfaces. It enables the direct, nondestructive visualization of elements developed on a TLC plate. In addition to inorganic compounds, organic compounds including electronegative elements can be detected simultaneously that cannot always be measured satisfactorily by competitive techniques; e.g., phenolic compounds containing chlorine, bromine, or iodine were distinctly detected by individual elemental imaging. The background of commercially available TLC plates with various thicknesses of the stationary phase and an outline of element detection limits were also investigated. TLC/XRF was found suitable for in situ TLC imaging of elements.

Deacetylation of chitin oligosaccharides of dp 2-4 by chitin deacetylase from Colletotrichum lindemuthianum.

Chitin oligosaccharides of degree of polymerization 2-4 were deacetylated by purified chitin deacetylase isolated from Colletotrichum lindemuthianum to give their corresponding breakdown products after purification by liquid chromatography. Data from FABMS analyses suggested that N,N',N",N"'-tetraacetylchitotetraose and N,N',N"-triacetylchitotriose were converted into fully-deacetylated corresponding chitosan oligomers. Conversely, N,N'-diacetylchitobiose [(GlcNAc)2] was deacetylated to give a product which showed an [M + H]+ pseudomolecular ion at m/z 383, suggesting that either of the two acetyl groups were removed. Further data from 1H NMR analyses confirmed that the reaction product was 2-acetamido-4-O-(2-amino-2-deoxy-beta-D-glucopyranosyl)-2-deoxy-D-glucos e [GlcN-GlcNAc]. The enzymatic method has three advantageous characteristics over chemical methods: (i) it does not cause unexpected degradation of the sugar chain, (ii) it is highly reproducible, and (iii) unique compounds such as GlcN-GlcNAc may be produced.

Identification of catechin oligomers from apple (Malus pumila cv. Fuji) in matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and fast-atom bombardment mass spectrometry.

Molecular size information for polymerized catechin larger than the decamer in unripe apple was obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and by fast-atom bombardment mass spectrometry. Matrix-assisted laser desorption/ionization time of flight mass spectrometry provided evidence for the pentadecamer using trans-3-indoleacrylic acid as the matrix in the presence of silver ion. Even in the absence of silver ion, the dodecamer and undecamer were observed in the positive- and negative-ion modes, respectively. Fast-atom bombardment mass spectrometry also afforded evidence for the undecamer in both positive- and negative-ion modes.

Purification and characterization of extracellular chin deacetylase from Colletotrichum lindemuthianum.

Chitin deacetylase, active in the presence of acetate (96% of the enzymatic activity was retained in the presence of 100 mM sodium acetate), was purified to electrophoretic homogeneity from a culture filtrate of Colletotrichum lindemuthianum (944-fold with a recovery of 4.05%). The enzyme was induced in the medium after the eighth day of incubation simultaneously with the blackening of the medium. The molecular mass of the enzyme was 31.5 kDa and 33 kDa as judged by SDS-PAGE and gel filtration, respectively, suggesting that the enzyme is a single polypeptide. The optimum temperature was 60 degrees C and the optimum pH was 11.5-12.0 when glycol chitin was used as substrate. The enzyme was active toward glycol chitin, partially N-deacetylated water soluble chitin, and chitin oligomers the degrees of polymerization of which were more than four, but was less active with chitin trimer and dimer, and inactive with N-acetylglucosamine. The Km and kcat for glycol chitin were 2.55 mM and 27.1 s-1, respectively, and those for chitin pentamer were 414 microM and 83.2 s-1, respectively. The reaction rates of the enzyme toward glycol chitin and chitin oligomers seemed to follow the Michaelis-Menten kinetics.

Triacylated anthocyanins from Ajuga reptans flowers and cell cultures.

Four anthocyanins were isolated from Ajuga reptans flowers and one from the cell cultures. By FAB mass spectrometry measurements, the structures of these pigments were determined as delphinidin and cyanidin glucosides acylated with two cinnamic acids, while three of them were also malonylated. A delphinidin-based pigment in the crude extract from cell cultures was identical to the major flower pigment as shown by HPLC co-chromatography. Moreover, by application of 1H and 13C NMR consisting of DQF-COSY, NOESY, ROESY, 2D-HOHAHA, HSQC and HMBC methods, the structures of two new anthocyanins were identified as delphinidin and cyanidin 3-O-(2-O-(6-O-(E)-p-coumaryl-beta-D-glucopyranosyl)-(6-O-(E)-p- coumaryl)-beta-D-glucopyranosyl)-5-O-(6-O-malonyl-beta-D-glucopyranoside ). The deacylated anthocyanins were confirmed as delphinidin and cyanidin 3-sophoroside-5-glucosides.