Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 70 , Issue 6
Showing 1-43 articles out of 43 articles from the selected issue
Analytical Chemistry Note
  • Naoko INOUE, Kazuaki AKASAKA, Hirokazu ARIMOTO, Hiroshi OHRUI
    2006 Volume 70 Issue 6 Pages 1517-1520
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    The chemiluminescence of gallic acid by hydrogen peroxide had completely inhibited by the presence of ascorbate. After ascorbate had disappeared by oxidation, chemiluminescence returned. The concentration of gallic acid was virtually unchanged by presence of ascorbate, but started to decrease after the disappearance of ascorbate. This might be attributable to the rapid reduction of quinone, which was the first product of the chemiluminescence reactions, to gallic acid by ascorbate or the donation of proton to the phenoxy radical from ascorbate to stop the chemiluminescence reaction at the first stage. The effects of ascorbate on the chemiluminescence of other polyphenols depended on their oxidation rate.
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Organic Chemistry Regular Paper
  • Eiichiro HAGINOYA, Hironobu HOJO, Yuko NAKAHARA, Yoshiaki NAKAHARA, Ka ...
    2006 Volume 70 Issue 6 Pages 1338-1349
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    The synthesis of a chitobiosylated peptide thioester by the t-butoxycarbonyl (Boc) strategy is demonstrated. Boc-Asn carrying benzyl-protected chitobiose was introduced during application of the Boc mode solid-phase method. HF treatment of the resulting protected peptide resin gave the desired chitobiosylated peptide thioester. This thioester was used to prepare the peptide sequence derived from extracellular matrix metalloproteinase inducers (emmprin) (34-94), (34-118) and (22-118) by the thioester segment condensation method. The conformation of these glycopeptides is characterized by circular dichroism (CD) spectral measurement.
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Organic Chemistry Note
Organic Chemistry Communication
  • Shin-ichi KATO, Yuichi OBA, Makoto OJIKA, Satoshi INOUYE
    2006 Volume 70 Issue 6 Pages 1528-1532
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    The emission of light in the marine ostracod Cypridina hilgendorfii (presently Vargula hilgendorfii) is produced by the Cypridina luciferin-luciferase reaction in the presence of molecular oxygen. Cypridina luciferin has an asymmetric carbon derived from isoleucine, and the absolute configuration is identical to the C-3 position in L-isoleucine or D-alloisoleucine. To determine the stereoselective incorporation of the isoleucine isomers (L-isoleucine, D-isoleucine, L-alloisoleucine, and D-alloisoleucine), we synthesized four 2H-labeled isoleucine isomers and examined their incorporation into Cypridina luciferin by feeding experiments. Judging by these results, L-isoleucine is predominantly incorporated into Cypridina luciferin. This suggests that the isoleucine unit of Cypridina luciferin is derived from L-isoleucine, but not from D-alloisoleucine.
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Biochemistry & Molecular Biology Regular Papers
  • Takashi YAMAZAKI, Yutaka OKAJIMA, Hiroki KAWASHIMA, Akira TSUKAMOTO, J ...
    2006 Volume 70 Issue 6 Pages 1293-1299
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    The homobasidiomycete Coriolus hirsutus coding sequences of a lignin peroxidase (LiP) gene (lip, containing six (I–VI) introns), a lip cDNA (lipc), and three lipc derivatives containing one (I), three (I–III), or five (I–V) introns were inserted into chromosome-integrating expression vector. These recombinant plasmids were introduced into C. hirustus monokaryotic strain. The transformant carrying the promoter–lipc–terminator cassette did not contain enough mRNA molecules to be detectable by Northern-blot analysis. On the other hand, all the transformants carrying cassettes of genomic lip and intron(s)-containing lipc sequences contained sufficient amounts of mRNAs to be easily detected by Northern-blot analysis. LiP activities in the culture supernatants of these transformants were found to be about five times as high as those of transformants carrying the lipc cassette (or no cassette). The culture supernatants of the transformants with high LiP activity showed remarkably high conversion activity toward pentachlorophenol (PCP) and degradation activity toward 2,7-dichlorodibenzo-p-dioxin (2,7-DCDD). These results indicate that at least one intron (intron I) is required for accumulation of lip mRNA and its subsequent translational expression in C. hirsutus.
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  • Akihito NISHIYAMA, Jun KANEKO, Masahiko HARATA, Yoshiyuki KAMIO
    2006 Volume 70 Issue 6 Pages 1300-1307
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    Staphylococcal leukocidin (Luk) consists of LukS and LukF, which cooperatively lyse human polymorphonuclear leukocytes (HPMNLs), monocytes, and macrophages. Here we found that LukS and LukF assembles into hetero-oligomeric pore complexes on the detergent-resistant membrane microdomains, lipid rafts of HPMNLs. When HPMNLs were treated with LukS alone, 24% of the added LukS was localized in lipid rafts. Furthermore, in HPMNLs treated with both LukS and LukF simultaneously, about 90% of high molecular-mass complexes of 100 kDa, which consists of LukS and LukF, were detected in the lipid raft fractions. In contrast, in HPMNLs treated with LukF alone, LukF was not localized in lipid rafts despite binding to the target cell membranes. Ten mM methyl-β-cyclodextrin, a dysfunctioning agent of lipid rafts, completely inhibited assembly of Luk on lipid rafts, and resulted in null leukocytolytic activity of Luk. Hence, we concluded that assembly of LukS and LukF into the pore-complex occurs in lipid rafts in HPMNLs and that LukF can bind to LukS, which had already bound to lipid rafts, to assemble into hetero-oligomers.
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  • Seonghun KIM, Sun Bok LEE
    2006 Volume 70 Issue 6 Pages 1308-1316
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    The thermoacidophilic archaeon Sulfolobus solfataricus is known to utilize D-glucose via the nonphosphorylated Entner-Doudoroff (ED) pathway. But, the genome database shows that this microorganism has a gene (kdgK) encoding 2-keto-3-deoxy-D-gluconate (KDG) kinase (KDGK) which phosphorylates KDG to 2-keto-3-deoxy-6-phosphogluconate. Interestingly, kdgK and three other genes in the modified ED pathway are organized as an operon-like structure. In this study, we report confirmation of the catalytic activity of the S. solfataricus KDGK protein. We also found that the kdgK gene was transcribed as polycistronic transcripts. Proteome analysis of cell lysate revealed that all gene products in the kdgK operon were expressed as functional proteins. These results strongly indicate that S. solfataricus metabolizes D-glucose via the ‘partially’ nonphosphorylated ED pathway. A purified recombinant S. solfataricus KDGK had Km and kcat values of 0.14 mM and 60.8 s−1 respectively for KDG, and showed maximal activity at temperatures between 70 and 80 °C and pHs between 7.0 and 8.0.
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  • Jin-Woo LEE, Dae-Seok NA, Ji-Yoon KANG, Sang-Ho LEE, Byeong-Kwon JU
    2006 Volume 70 Issue 6 Pages 1325-1330
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    Mouse P19 embryonic carcinoma (EC) stem cells were xenotransplanted into the emptied chorion, the transparent envelope of a fertilized zebrafish egg (rather than mouse native zona pellucida) combined with a microfluidic device to study P19 EC cell differentiation in the chorion biomaterial. A distilled-water jet was used to remove the innate yolk and perivitelline inner mass from the chorion. P19 EC cells were injected into the emptied chorion using a micropipette, and they were subsequently cultured until the inner space of the chorion became completely occupied by cells. A simple microfluidic device was used for handling convenience and effective experiment. At d15, we found neural cells in the outer layer of the cell mass and beating cardiomyocytes in the inner layer of the large embryoid body. We propose that even though the species are different, the external innate membranes developed for embryo protection represent a useful type of ECM.
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  • Hiroyuki SUGIYAMA, Masashi SONOYAMA, Ganga D. GHIMIRE, Shigeki MITAKU
    2006 Volume 70 Issue 6 Pages 1350-1355
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    Measurements of regeneration kinetics were performed in order to investigate the regeneration mechanisms of bacteriorhodopsin (bR) from thermally unfolded bacterio-opsin (bO) and all-trans retinal. Regeneration kinetics data were successfully fitted to a single exponential function when regeneration was performed at 25 °C after incubation at high temperatures. Conversely, the process of regeneration after the addition of retinal to bO at high temperatures occurred at two different rate constants. These findings strongly suggest that the slower regeneration of bR at high temperatures occurs as a result of dynamic structural fluctuation of bO, whereas the faster process corresponds to regeneration from bO, which retains a native structure capable of retinal binding.
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  • Megumi MAEDA, Yoshinobu KIMURA
    2006 Volume 70 Issue 6 Pages 1356-1363
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    Although it has been found that plant endo-β-N-acetylglucosaminidase shows strong activity towards denatured glycoproteins and glycopeptides with high-mannose type N-glycans and free high-mannose type N-glycans bearing the chitobiosyl unit, the endogenous substrates for plant endoglycosidase have not yet been identified. Recently we purified and characterized an endo-β-N-acetylglucosaminidase from rice culture cells and identified the gene encoded (Maeda, M., and Kimura, Y., Trends Glycosci. Glycotech., 17, 205–214 (2005)). Furthermore, we found structural features of free N-glycans in the cells, indicating that high-mannose type species (Man9-5GlcNAc1) occur at concentration of several micromolar (μM). Hence, in this study we analyzed glycoform of N-glycans linked to glycoproteins expressed in rice culture cells to see whether endogenous glycoproteinous substrate occurs in reasonable amounts. Structural analysis revealed that more than 95% of total N-glycans linked to glycoproteins in the rice cells had the plant complex type structure, including Lewis a epitope-harboring type, although high-mannose type structures account for less than 5% of total N-glycans.
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  • Sayaka KAZAMI, Makoto MUROI, Makoto KAWATANI, Takaaki KUBOTA, Takeo US ...
    2006 Volume 70 Issue 6 Pages 1364-1370
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    Iejimalides (IEJLs), 24-membered macrolides, are potent antitumor compounds, but their molecular targets remain to be revealed. In the course of screening, we identified IEJLs as potent osteoclast inhibitors. Since it is known that osteoclasts are sensitive to vacuolar H+-ATPase (V-ATPase) inhibitor, we investigated the effect of IEJLs on V-ATPases. IEJLs inhibited the V-ATPases of both mammalian and yeast cells in situ, and of yeast V-ATPases in vitro. A bafilomycin-resistant yeast mutant conferred IEJL resistance, suggesting that IEJLs bind a site similar to the bafilomycins/concanamycins-binding site. These results indicate that IEJLs are novel V-ATPase inhibitors, and that antitumor and antiosteporotic activities are exerted via V-ATPase inhibition.
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  • Sirilak NAMWONG, Kazumi HIRAGA, Katsumi TAKADA, Masahiko TSUNEMI, Somb ...
    2006 Volume 70 Issue 6 Pages 1395-1401
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    A halophilic bacterium was isolated from fish sauce, classified, and named Halobacillus sp. SR5-3. A purified 43-kDa proteinase produced by this bacterium showed optimal activity at 50 °C and pH 9–10 in 20% NaCl. The activity of the enzyme was enhanced about 2.5-fold by the addition of 20–35% NaCl, and the enzyme was highly stabilized by NaCl. It was found to be a serine proteinase related to either chymotrypsin or subtilisin. It absolutely preferred Ile at the P2 position of substrates. Thus, the enzyme was found to be a halophilic serine proteinase with unique substrate specificity.
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  • Kiminori TOYOOKA, Fenzhi LIU, Motoshi ISHII, Shouichiro SAITO, Teruo K ...
    2006 Volume 70 Issue 6 Pages 1402-1407
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    The 65-kDa protein (p65) was previously identified as a phosphorylated protein in activated macrophages, and has turned out to be a member of a plastin protein family characterized by a series of Ca2+-, calmodulin-, and β-actin-binding domains. In mice, two isoforms, p65/L-plastin and T-plastin, have so far been identified; p65/L-plastin is expressed in hemopoietic cells and cancer cells, and T-plastin in solid tissue cells. We generated monoclonal antibodies to p65/L-plastin, examined the isoform-specificity by using recombinant (r) T-plastin, and found that the antibodies were specific for rp65/L-plastin, whereas immune sera to rp65/L-plastin showed cross-reactions to rT-plastin. One of the antibodies, p65-7B5, was demonstrated to react to native p65/L-plastin by Western blot, flow cytometric, and immunohistochemical analysis. Furthermore, p65-7B5 has made it possible to detect p65/L-plastin-expressing cells in tissues where T-plastin is abundantly expressed. These reagents and procedures should provide specific tools to investigate the role of p65/L-plastin in leukocytes.
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  • Mahboob MORSHED, Shusuke SANO, Daisuke NISHIMIYA, Munetoshi ANDO, Ken- ...
    2006 Volume 70 Issue 6 Pages 1438-1446
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    Here we report the methylation status of the chicken ovalbumin promoter. Genomic DNA of oviduct from immature chickens and laying hens was analyzed through bisulfite genomic sequencing. In the ovalbumin control locus up to the 6 kb upstream region, CpG sites were methylated in immature chickens, except for several sites, and almost all CpGs residing in DNase I hypersensitive sites I, II, and III, but not IV, were selectively unmethylated in ovalbumin expressing chickens. Chromatin immunoprecipitation assays showed that the ovalbumin control region was associated with acetylated histone H3 but not with dimethylated histone H3 at Lys 27. These results demonstrate that DNA demethylation was restricted to short DNA regions of DNase I hypersensitive sites, especially to those which participated in estrogen-responsiveness, even when cells expressed extremely high levels of ovalbumin and these sites were associated with acetylated histones.
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  • Atsushi ISHIKAWA, Yuri KIMURA, Michiko YASUDA, Hideo NAKASHITA, Shigeo ...
    2006 Volume 70 Issue 6 Pages 1447-1453
    Published: June 23, 2006
    Released: June 23, 2006
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    The Arabidopsis lesion initiation 3 (len3) mutant develops lesions on leaves without pathogen attack. len3 plants exhibit stunted growth, constitutively express pathogenesis-related (PR) genes, PR-1, PR-2, and PR-5, and accumulate elevated levels of salicylic acid (SA). Furthermore, len3 is a semidominant, male gametophytic lethal mutation with partial defects in female gametophytic development. To determine the signaling pathway activated in len3 plants, we crossed the len3 plants with nahG, npr1-1, and pad4-1 plants and analyzed the phenotypes of the double mutants. The len3-conferred phenotypes, including cell death and PR-1 expressions, were suppressed in the double mutants. Thus SA, NPR1, and PAD4 are required for the phenotypes. However, none of these double mutants could completely suppress the len3-conferred stunted growth. This result suggests that an SA-, NPR1-, and PAD4-independent pathway is also involved in the phenotype. Treatment with BTH (benzo(1,2,3)thiadiazole-7-carbothioic acid), an SA analog, induced cell death in len3 nahG plants but not in len3 npr1 or len3 pad4 plants, suggesting the involvement of the PAD4-dependent but SA-independent second signal pathway in cell death in len3 plants.
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  • Jeong Ho KIM, Bong Gyu KIM, Younghee PARK, Jae Hyung KO, Chae Eun LIM, ...
    2006 Volume 70 Issue 6 Pages 1471-1477
    Published: June 23, 2006
    Released: June 23, 2006
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    Most flavonoids found in plants exist as glycosides, and glycosylation status has a wide range of effects on flavonoid solubility, stability, and bioavailability. Glycosylation of flavonoids is mediated by Family 1 glycosyltransferases (UGTs), which use UDP-sugars, such as UDP-glucose, as the glycosyl donor. AtGT-2, a UGT from Arabidopsis thaliana, was cloned and expressed in Escherichia coli as a gluthatione S-transferase fusion protein. Several compounds, including flavonoids, were tested as potential substrates. HPLC analysis of the reaction products indicated that AtGT-2 transfers a glucose molecule into several different kinds of flavonoids, eriodictyol being the most effective substrate, followed by luteolin, kaempferol, and quercetin. Based on comparison of HPLC retention times with authentic flavonoid 7-O-glucosides and nuclear magnetic resonance spectroscopy, the glycosylation position in the reacted flavonoids was determined to be the C-7 hydroxyl group. These results indicate that AtGT-2 encodes a flavonoid 7-O-glucosyltransferase.
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Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Communications
Food & Nutrition Science Regular Papers
  • Mitsuharu MATSUMOTO, Yoshimi BENNO
    2006 Volume 70 Issue 6 Pages 1287-1292
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    There is little evidence for a relationship between probiotic metabolites and host cytokine production. We investigated in the present study the possibility that anti-inflammatory metabolites can be produced in the gut by LKM512 yogurt consumption by using murine macrophage-like J774.1 cells and extracts prepared from the feces of elderly volunteers. These volunteers’ acute inflammation had been inhibited by LKM512 yogurt consumption in a previous test. The tumor necrosis factor (TNF)-α production elicited in J774.1 cells stimulated by lipopolysaccharide (LPS) and in the fecal extracts obtained during the period of LKM512 yogurt consumption was significantly decreased (p<0.05) than the pre-consumption baseline level. These findings and previous data enable us to conclude that intestinal bacterial metabolites produced by LKM512 yogurt consumption contributed to suppressing the inflammatory cytokine produced by macrophages and that one of the anti-inflammatory metabolites in the fecal extracts was likely to have been a polyamine.
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  • Atsushi YOKOMIZO, Masamitsu MORIWAKI
    2006 Volume 70 Issue 6 Pages 1317-1324
    Published: June 23, 2006
    Released: June 23, 2006
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    The relation between the uptake of flavonoids and the response of human colon adenocarcinoma Caco-2 cells exposed to oxidative stress induced by hydrogen peroxide (H2O2) was examined. Flavonoid aglycones were incorporated into Caco-2 cells in a concentration- and time-dependent manner, but neither glycosides nor unstable myricetin were incorporated into the cells. The incorporated flavonoids reduced the reactive oxygen species (ROS) induced by H2O2 in the cells in proportion to the amount incorporated and the radical scavenging activity of flavonoids. But, flavonoids with high radical scavenging activity also generated H2O2. The activity decreasing intracellular ROS was inversely related to the H2O2 scavenging activity of flavonoids. Therefore, the decrease in the amount of intracellular ROS induced by H2O2 was not directly due to the scavenging of H2O2, but rather to the scavenging of ROS generated from H2O2. These results suggest that strong antioxidative flavonoids have both a cytoprotective effect owing to the scavenging of ROS and cytotoxic effect caused by the generation of H2O2.
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  • Katsumi SHIBATA, Tsutomu FUKUWATARI, Yoriko IGUCHI, Yuko KURATA, Miki ...
    2006 Volume 70 Issue 6 Pages 1331-1337
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    In order to find an alleviation method for the adverse effect of environmental endocrine disrupters, we studied the effects of the putative endocrine disrupter and peroxisome proliferator, di(2-ethylhexyl)phthalate (DEHP), on animal growth and vitamin metabolism. It is known that the effects of chemical compounds such as xenobiotics differ according to the dietary protein source. We compared the effects of dietary DEHP administration on rats fed with a diet containing milk casein or wheat gluten. The increased conversion ratio of tryptophan to nicotinamide by DEHP administration was significantly higher in the casein group than in the gluten group. We also investigated the effects of DEHP on the urinary excretion of other vitamins. DEHP administration resulted in decreased urinary excretion of vitamin B1, vitamin B2, and pantothenic acid.
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  • Mika YAMADA, Fujimi TANABE, Norie ARAI, Hitoshi MITSUZUMI, Yoshikatsu ...
    2006 Volume 70 Issue 6 Pages 1386-1394
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    Glucosyl hesperidin (G-hesperidin) is a water-soluble derivative of hesperidin. We compared the absorption and metabolism of G-hesperidin with those of hesperidin in rats. After oral administration of G-hesperidin or hesperidin to rats, hesperetin was detected in sera hydrolyzed with β-glucuronidase, but it was not detectable in unhydrolyzed sera. Serum hesperetin was found more rapidly in rats administered G-hesperidin than in those administered hesperidin. The area under the concentration-time curve for hesperetin in the sera of rats administered G-hesperidin was approximately 3.7-fold greater than that of rats administered hesperidin. In the urine of both administration groups, hesperetin and its glucuronide were found. Urinary excretion of metabolites was higher in rats administered G-hesperidin than in those administered hesperidin. These results indicate that G-hesperidin presents the same metabolic profile as hesperidin. Moreover, it was concluded that G-hesperidin is absorbed more rapidly and efficiently than hesperidin, because of its high water solubility.
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  • Akiko TAMURA, Hadzuki NINO, Tomoko MINOBE, Violeta G RANEVA, Norihiro ...
    2006 Volume 70 Issue 6 Pages 1416-1422
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    We evaluated the body energy accumulation as fat and protein from ingestion of difructose anhydride III (DFAIII). Male Wistar rats were fed 0, 0.25, 0.5, 1.0, or 1.5 g per d of sucrose or DFAIII added to a 7 g of basal diet for 20 d. Supplements of DFAIII did not increase whole body or peripheral fat or total body energy, whereas sucrose increased them in a dose-dependent manner. Dose-dependent increases in body water were observed in both groups. The body protein was influenced by the dose of sugars. The estimated available energy value of DFAIII was 0.263 kcal per gram; this value is one-fifteenth that of sucrose. Ingestion of DFAIII dose-dependently increased the cecal SCFA pool. DFAIII was not detected in feces, showing complete degradation of DFAIII in the intestine. These results indicate that DFAIII is a fermentable saccharide with quite low available energy for fat accumulation.
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  • Miwako KUSUDA, Kazutoshi INADA, Tomo-omi OGAWA, Takashi YOSHIDA, Sumik ...
    2006 Volume 70 Issue 6 Pages 1423-1431
    Published: June 23, 2006
    Released: June 23, 2006
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    Zanthoxylum piperitum (Rutaceae) is used as a spice and a natural medicine in Japan. Our study found that ZP-CT-A, a polymeric proanthocyanidin purified from the fruit of this species, noticeably decreased the minimum inhibitory concentrations of β-lactam antibiotics for methicillin-resistant Staphylococcus aureus (MRSA). The structure of ZP-CT-A was characterized on the basis of 13C NMR and size exclusion chromatographic data and the results of thiolytic degradation. A mechanistic study of the effects of ZP-CT-A indicated that it suppressed the activity of β-lactamase and largely decreased the stability of the bacterial cell membrane of MRSA, as shown by a reduction in the tolerance of MRSA to low osmotic pressure and high ionic strength solutions.
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  • Kyu-Ho HAN, Naoto HASHIMOTO, Ken-ichiro SHIMADA, Mitsuo SEKIKAWA, Taka ...
    2006 Volume 70 Issue 6 Pages 1432-1437
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    We investigated the hepatoprotective effect of purple potato extract (PPE) against D-galactosamine (GalN)-induced liver injury in rats. PPE (400 mg) was administered once daily for 8 d, and then GalN (250 mg/kg of body weight) was injected at 22 h before the rats were killed. Serum tumor necrosis factor alpha (TNF-α), lactate dehydrogenase (LDH), alanine aminotransferase (ALT), and asparate aminotranferase (AST) levels increased significantly after injection of GalN, but PPE inhibited GalN-induced alterations in serum TNF-α, LDH, ALT, and AST levels. Hepatic lipid peroxide and glutathione levels in the control + GalN group were higher and lower respectively than those in the control group, and those in the PPE + GalN group did not differ from that in the control group. The lipid peroxide level in hepatic microsomes treated with 2,2′-azobis (2-amidinopropane) dihydrochloride in the PPE group was significantly lower than that in the control group. This suggests that PPE has hepatoprotective effects against GalN-induced hepatotoxicity via inhibition lipid peroxidation and/or inflammation in rats.
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  • Sachiko NARASAKA, Yoshie ENDO, Zhengwei FU, Megumi MORIYAMA, Soichi AR ...
    2006 Volume 70 Issue 6 Pages 1464-1470
    Published: June 23, 2006
    Released: June 23, 2006
    [Advance publication] Released: June 01, 2006
    JOURNALS FREE ACCESS
    The effect of the consumption of hypoallergenic wheat flour (HWF) on the expression of a wide spectrum of genes was analyzed by using a DNA microarray. Gene expression profiles in the liver and intestines of rats fed on a diet composed mainly of HWF were compared with those of rats fed on a normal flour-based diet. Among the eight thousand transcripts represented on the GeneChip microarray, no more than 30 genes exhibited up- or down-regulation of two-fold or more after one week or two months of HWF consumption. No adverse effects were apparent. Up-regulation of some of the genes known to respond to the interferon-γ signal was apparent in the one-week experiment, which may be related to possible oral immunotolerance resulting from HWF feeding. This DNA microarray technology presents an efficient method for evaluating the safety of foods.
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  • Ali A. MOAZZAMI, Rolf E. ANDERSSON, Afaf KAMAL-ELDIN
    2006 Volume 70 Issue 6 Pages 1478-1481
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    A new lignan glucoside was isolated from defatted sesame seed flour and its structure was established as sesamolinol diglucoside [2-(3-methoxy-4-(O-β-D-glucopyranosyl (1→6)-O-β-D-glucopyranoside)phenoxyl)-6-(3,4-methylenedioxyphenyl)-cis-3,7-dioxabicyclo-(3.3.0)-octane] by mass and nuclear magnetic resonance spectroscopy. A quantitative analysis of 65 sesame seed samples showed that this sesamolinol diglucoside ranged from <5 to 232 mg/100 g of seeds (98±57 mg/100 g) with no difference between white and black sesame seeds.
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Food & Nutrition Science Notes
Food & Nutrition Science Communication
  • Yutaka MIURA, Taro NAKAZAWA, Kazumi YAGASAKI
    2006 Volume 70 Issue 6 Pages 1533-1536
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    L-Leucine is known to stimulate protein synthesis in L6 myotubes. In the present study, we examined the possible involvement of calcium signaling pathways in the stimulation of protein synthesis induced by L-leucine in L6 myotubes. After 16 h of treatment with L-leucine-depleted medium, the re-addition of L-leucine for 4 h augmented protein synthesis by about 50% as compared with an L-leucine-depleted control. Ryanodine receptor antagonists almost completely abolished the stimulatory effect of L-leucine, while IP3 receptor antagonists showed partial inhibition when added simultaneously with L-leucine. These results suggest the possibility that calcium signaling pathways are involved in L-leucine-stimulated protein synthesis.
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Microbiology & Fermentation Technology Regular Papers
  • Nobuyuki HORINOUCHI, Jun OGAWA, Takako KAWANO, Takafumi SAKAI, Kyota S ...
    2006 Volume 70 Issue 6 Pages 1371-1378
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    2-Deoxyribose 5-phosphate production through coupling of the alcoholic fermentation system of baker’s yeast and deoxyriboaldolase-expressing Escherichia coli was investigated. In this process, baker’s yeast generates fructose 1,6-diphosphate from glucose and inorganic phosphate, and then the E. coli convert the fructose 1,6-diphosphate into 2-deoxyribose 5-phosphate via D-glyceraldehyde 3-phosphate. Under the optimized conditions with toluene-treated yeast cells, 356 mM (121 g/l) fructose 1,6-diphosphate was produced from 1,111 mM glucose and 750 mM potassium phosphate buffer (pH 6.4) with a catalytic amount of AMP, and the reaction supernatant containing the fructose 1,6-diphosphate was used directly as substrate for 2-deoxyribose 5-phosphate production with the E. coli cells. With 178 mM enzymatically prepared fructose 1,6-diphosphate and 400 mM acetaldehyde as substrates, 246 mM (52.6 g/l) 2-deoxyribose 5-phosphate was produced. The molar yield of 2-deoxyribose 5-phosphate as to glucose through the total two step reaction was 22.1%. The 2-deoxyribose 5-phosphate produced was converted to 2-deoxyribose with a molar yield of 85% through endogenous or exogenous phosphatase activity.
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  • Tadashi FUJII, Tatsuya NARIKAWA, Futoshi SUMISA, Akira ARISAWA, Koji T ...
    2006 Volume 70 Issue 6 Pages 1379-1385
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    Our biotransformation using Escherichia coli expressing a cytochrome P450 (CYP) belonging to the CYP153A family from Acinetobacter sp. OC4 produced a great amount of 1-octanol (2,250 mg per liter) from n-octane after 24 h of incubation. This level of production is equivalent to the maximum level previously achieved in biotransformation experiments of alkanes. In addition, the initial production rate of 1-octanol was maintained throughout the entire incubation period. These results indicate that we have achieved the functional and stable expression of a CYP in E. coli for the first time. Further, our biotransformation system showed α,ω-diterminal oxidation activity of n-alkanes, and a large amount of 1,8-octanediol (722 mg per liter) was produced from 1-octanol after 24 h of incubation. This is the first report on the bioproduction of α,ω-alkanediols from n-alkanes or 1-alkanols.
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  • Yasuaki WADA, Takanori KOBAYASHI, Michiko TAKAHASHI, Hiromi NAKANISHI, ...
    2006 Volume 70 Issue 6 Pages 1408-1415
    Published: June 23, 2006
    Released: June 23, 2006
    JOURNALS FREE ACCESS
    Nicotianamine (NA), a metal chelator, is ubiquitous in higher plants. In humans, NA inhibits angiotensin I-converting enzyme (ACE), and consequently reduces high blood pressure. Nicotianamine is synthesized from the trimerization of S-adenosylmethionine (SAM) by NA synthase (NAS). Here, we aimed to produce large amounts of NA fermentatively by introducing the Arabidopsis AtNAS2 gene into Saccharomyces cerevisiae strain SCY4. This strain can accumulate up to 100 times the usual amount of SAM, and this is considered desirable for overproduction of NA. Nicotianamine was produced in the engineered yeast, and the NA level increased with incubation time until the stationary phase. The maximum concentration of intracellular NA obtained was 766±33 μg/g wet weight. Successful production of NA in S. cerevisiae should pave the way for industrial production of this novel antihypertensive substrate.
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  • Tomotake MORITA, Naotaka TANAKA, Akira HOSOMI, Yuko GIGA-HAMA, Kaoru T ...
    2006 Volume 70 Issue 6 Pages 1454-1463
    Published: June 23, 2006
    Released: June 23, 2006
    [Advance publication] Released: June 01, 2006
    JOURNALS FREE ACCESS
    Glycosylphosphatidylinositol (GPI)-anchored proteins are essential for normal cellular morphogenesis and have an additional role in mediating cross-linking of glycoproteins to cell wall glucan in yeast cells. Although many GPI-anchored proteins have been characterized in Saccharomyces cerevisiae, none have been reported for well-characterized GPI-anchored proteins in Schizosaccharomyces pombe to date. Among the putative GPI-anchored proteins in S. pombe, four α-amylase homologs (Aah1p-Aah4p) have putative signal sequences and C-terminal GPI anchor addition signals. Disruption of aah3+ resulted in a morphological defect and hypersensitivity to cell wall-degrading enzymes. Biochemical analysis showed that Aah3p is an N-glycosylated, GPI-anchored membrane protein localized in the membrane and cell wall fractions. Conjugation and sporulation were not affected by the aah3+ deletion, but the ascal wall of aah3Δ cells was easily lysed by hydrolases. Expression of aah3 alleles in which the conserved aspartic acid and glutamic acid residues required for hydrolase activity were replaced with alanine residues failed to rescue the morphological and ascal wall defects of aah3Δ cells. Taken together, these results indicate that Aah3p is a GPI-anchored protein and is required for cell and ascal wall integrity in S. pombe.
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Microbiology & Fermentation Technology Notes
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