Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 70 , Issue 11
Showing 1-38 articles out of 38 articles from the selected issue
Analytical Chemistry Notes
  • Hye Hyun YOO, Jeong Hill PARK, Sung Won KWON
    2006 Volume 70 Issue 11 Pages 2783-2785
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    The lignan glycoside, tracheloside, was isolated from seeds of Carthamus tinctorius (Compositae) as an anti-estrogenic principle against cultured Ishikawa cells by employing a bioassay-linked HPLC-ELSD method. Tracheloside significantly decreased the activity of alkaline phosphatase (AP), an estrogen-inducible marker enzyme, with an IC50 value of 0.31 μg/ml, a level of inhibition comparable to that of tamoxifen (IC50 = 0.43 μg/ml).
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  • Takamitsu CHAKI, Hideto KAKIMI, Akihiro SHIBATA, Takashi BABA
    2006 Volume 70 Issue 11 Pages 2793-2796
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    We attempted in this study to detect alginate oligosaccharides (AO) from mollusks. The samples used were digestive organs taken from turban shells and abalones which commonly ate brown algae. High-performance liquid chromatography (HPLC) and negative-ion electrospray ionization (ESI) quadrupole time-of-flight (Q-TOF) mass spectrometry (MS) analyses were used to confirm the presence of AO. Samples spiked with AO resulted in observable peaks where the HPLC area was increased. The highest content was estimated to be 401.8 mg/100 g of digestive organ. The product-ion data derived from AO molecular weight were detected at a constant interval by Q-TOF MS/MS analysis. These findings indicate that AO was present in the digestive organs of mollusks.
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Organic Chemistry Notes
Biochemistry & Molecular Biology Regular Papers
  • Masataka NARUKAWA, Tomohiko MORI, Yukako HAYASHI
    2006 Volume 70 Issue 11 Pages 2613-2619
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    Recently, candidates for umami receptors have been identified in taste cells, but the precise transduction mechanisms of the downstream receptor remain unknown. To investigate how intracellular Ca2+ increases in the umami transduction pathway, we measured changes in intracellular Ca2+ levels in response to umami stimuli monosodium glutamate (MSG), IMP, and MSG + IMP in mouse taste receptor cells (TRCs) by Ca2+ imaging. Even when extracellular Ca2+ was absent, 1/3 of umami-responsive TRCs exhibited increased intracellular Ca2+ levels. When intracellular Ca2+ was depleted, half of the TRCs retained their response to umami. These results suggest that umami-responsive TRCs increase their intracellular Ca2+ levels through two pathways: by releasing Ca2+ from intracellular stores and by an influx of Ca2+ from extracellular sources. We conclude that the Ca2+ influx from extracellular source might play an important role in the synergistic effect between MSG and IMP.
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  • Tzyy-Rong JINN, Chi-Ming WU, Wu-Chun TU, Jiunn-Liang KO, Jason T. C. T ...
    2006 Volume 70 Issue 11 Pages 2627-2634
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    The mushrooms of diverse Lingzhi species have been traditionally consumed as luxurious functional food supplements in Chinese society. FIP-gts, a fungal immunomodulatory protein found in Song-Shan Lingzhi (Ganodera tsugae) has been proposed to possess therapeutic effects on cancer and autoimmune diseases. To produce active FIP-gts for evaluation of oral administration, a recombinant FIP-gts (rFIP-gts) fused with a 6His-tag at its C-terminus was expressed in Sf21 insect cells by the baculovirus expression system. High yield (about 70%) and purity (about 90%) of rFIP-gts was obtained by one-step nickel-affinity chromatography. The correctness of the harvested rFIP-gts was verified by Western blot and MALDI-MS analyses. Optimal expression of rFIP-gts was observed when the Sf21 cells were infected with multiplicity of infection of 10 for 72 h, and the yield was up to 47.2 μg/3×106 infected cells. The immunomodulatory activity of the purified rFIP-gts was detected as the induction of interleukin 2 released from murine splenocytes. Compared with the rFIP-gts produced in Escherichia coli cells, the rFIP-gts produced in Sf21 cells possessed evidently higher specific immunomodulatory activity.
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  • Woan-Sub KIM, Kei-ichi SHIMAZAKI, Tomohiro TAMURA
    2006 Volume 70 Issue 11 Pages 2641-2645
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    A Rhodococcus erythropolis expression system for the bovine lactoferrin C-lobe was constructed. The DNA fragments encoding the BLF C-lobe were amplified and cloned into vector pTip LCH1.2. R. erythropolis carrying the pTip-C-lobe was cultured at 30 °C with shaking, and expression of the rBLF C-lobe was induced by adding 1 μg/ml (final concentration) thiostrepton. The rBLF C-lobe was isolated in native and denatured (8 M urea) form by Ni-NTA affinity chromatography. To obtain a bioactive rBLF C-lobe, the protein isolated in the denatured form was refolded by stepwise dialysis against refolding buffers. The antibacterial activity of the rBLF C-lobe was tested by the filter-disc plate assay method. The refolded rBLF C-lobe demonstrated antibacterial activity against selected strains of Escherichia coli.
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  • Yuya KASAJIMA, Masako YAMAGUCHI, Nobuaki HIRAI, Tetsuo OHMACHI, Takash ...
    2006 Volume 70 Issue 11 Pages 2662-2668
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    UDP-N-Acetylglucosamine: α-3-D-mannoside β-1,2-N-acetylglucosaminyltransferase I (GnT-I) is an essential enzyme in the conversion of high mannose type oligosaccharide to the hybrid or complex type. The full length of the rat GnT-I gene was expressed in the filamentous fungus Aspergillus oryzae. A microsomal preparation from a recombinant fungus (strain NG) showed GnT-I activity that transferred N-acetylglucosamine residue to acceptor heptaose, Man5GlcNAc2. The N-linked sugar chain of α-amylase secreted by the strain showed a peak of novel retention on high performance liquid chromatography that was same as a reaction product of in vitro GnT-1 assay. The peak of oligosaccharide disappeared on HPLC after β-N-acetylglucosaminidase treatment. Mass analysis supported the presence of GlcNAcMan5GlcNAc2 as a sugar chain of α-amylase from strain NG. Chimera of GnT-I with green fluorescent protein (GFP) showed a dotted pattern of fluorescence in the mycelia, suggesting localization at Golgi vesicles. We concluded that GnT-1 was functionally expressed in A. oryzae cells and that N-acetylglucosamine residue was transferred to N-glycan of α-amylase in vivo. A. oryzae is expected to be a potential host for the production of glycoprotein with a genetically altered sugar chain.
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  • Shuzo IKUTA, Nobufumi SEKINO, Takeshi HARA, Yuriko SAITO, Kazuhiro CHI ...
    2006 Volume 70 Issue 11 Pages 2669-2675
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    We describe an organotypic model of mouse skin consisting of a stratified sheet of epidermal keratinocytes and dermal fibroblasts within a contracted collagen gel. The model was designed to maintain the polarity of stratified keratinocytes and permit their long-term culture at an air-liquid interface. After air exposure, the thickness of the keratinocyte sheet transiently increased and then decreased to two cell layers at 2 weeks. The two-cell-layer structure is similar to that of the adult mouse epidermis. Cytokeratin 5 was localized in the lowest cell layer in the epithelial sheet, but cytokeratin 1 and loricrin were localized in the outer cell layers, resembling mouse skin. The expressions of interleukin 1α and 1β in the keratinocytes and of keratinocyte growth factor 1 and 2 in the fibroblasts correlated with keratinocyte stratification. The mouse organotypic coculture is useful in studying epithelial cell-mesenchymal cell interactions in vitro.
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  • Osamu HAYASHI, Kiyoshi SATOH
    2006 Volume 70 Issue 11 Pages 2676-2681
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    A highly sensitive and selective analytical method was developed to determine levels of acetyl-CoA and malonyl-CoA in plant tissues. The analytical method includes a convenient extraction method for plant samples and a new LC-MS/MS technique utilizing an ion pair reagent. These acyl-CoAs, present in germinating rice seeds, were then determined by the method developed. It was found that the concentrations of both acetyl-CoA and malonyl-CoA increased with time during the germination of rice seeds and also increased at the elevated cultivation temperatures among tested. These results reflect the development of enzymes that produce these acyl-CoAs in germinating rice seeds.
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  • Makiko AICHI, Saori YOSHIHARA, Madoka YAMASHITA, Shin-ichi MAEDA, Kazu ...
    2006 Volume 70 Issue 11 Pages 2682-2689
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    The products of the NpR1527 and NpR1526 genes of the filamentous, diazotrophic, fresh-water cyanobacterium Nostoc punctiforme strain ATCC 29133 were identified as a nitrate transporter (NRT) and nitrate reductase (NR) respectively, by complementation of nitrate assimilation mutants of the cyanobacterium Synechococcus elongatus strain PCC 7942. While other fresh-water cyanobacteria, including S. elongatus, have an ATP-binding cassette (ABC)-type NRT, the NRT of N. punctiforme belongs to the major facilitator superfamily, being orthologous to the one found in marine cyanobacteria (NrtP). Unlike the ABC-type NRT, which transports both nitrate and nitrite with high affinity, Nostoc NrtP transported nitrate preferentially over nitrite. NrtP was distinct from ABC-type NRT also in its insensitivity to ammonium-promoted regulation at the post-translational level. The nitrate reductase of N. punctiforme was, on the other hand, inhibited upon addition of ammonium to medium, lending ammonium sensitivity to nitrate assimilation.
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  • Hikaru WATANABE, Tomoyuki NISHIMOTO, Michio KUBOTA, Hiroto CHAEN, Shig ...
    2006 Volume 70 Issue 11 Pages 2690-2702
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    The gene for a novel glucanotransferase, isocyclomaltooligosaccharide glucanotransferase (IgtY), involved in the synthesis of a cyclomaltopentaose cyclized by an α-1,6-linkage [ICG5; cyclo-{→6)-α-D-Glcp-(1→4)-α-D-Glcp-(1→4)-α-D-Glcp-(1→4)-α-D-Glcp-(1→4)-α-D-Glcp-(1→}] from starch, was cloned from the genome of B. circulans AM7. The IgtY gene, designated igtY, consisted of 2,985 bp encoding a signal peptide of 35 amino acids and a mature protein of 960 amino acids with a calculated molecular mass of 102,071 Da. The deduced amino-acid sequence showed similarities to 6-α-maltosyltransferase, α-amylase, and cyclomaltodextrin glucanotransferase. The four conserved regions common in the α-amylase family enzymes were also found in this enzyme, indicating that this enzyme should be assigned to this family. The DNA sequence of 8,325-bp analyzed in this study contained two open reading frames (ORFs) downstream of igtY. The first ORF, designated igtZ, formed a gene cluster, igtYZ. The amino-acid sequence deduced from igtZ exhibited no similarity to any proteins with known or unknown functions. IgtZ was expressed in Escherichia coli, and the enzyme was purified. The enzyme acted on maltooligosaccharides that have a degree of polymerization (DP) of 4 or more, amylose, and soluble starch to produce glucose and maltooligosaccharides up to DP5 by a hydrolysis reaction. The enzyme (IgtZ), which has a novel amino-acid sequence, should be assigned to α-amylase. It is notable that both IgtY and IgtZ have a tandem sequence similar to a carbohydrate-binding module belonging to a family 25. These two enzymes jointly acted on raw starch, and efficiently generated ICG5.
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  • Masaaki WACHI, Kazuyoshi OSAKA, Tomoko KOHAMA, Kumi SASAKI, Iwao OHTSU ...
    2006 Volume 70 Issue 11 Pages 2712-2719
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    The Escherichia coli mreB gene encodes an actin-like cytoskeletal protein and is required for rod shape formation of cells and chromosome segregation. Just downstream of mreB, the mreC and mreD genes are located. They are also required for rod shape formation, though their role in chromosome segregation is unclear. lacZ fusion analysis and Northern hybridization showed that the mreB, mreC, and mreD genes formed an operon. Most of the transcripts were expressed as a monocistronic mreB mRNA, and only 1–2% of the transcripts were expressed as a polycistronic mreBCD mRNA. Introduction of a frame-shift mutation in the mreB gene resulted in a significant decrease in the amount of polycistronic mreBCD mRNA but not in that of monocistronic mreB mRNA, suggesting that an attenuation-like regulation was involved in this transcriptional control. Primer extension analysis identified three transcriptional initiation sites. Three possible σD-dependent promoter-like sequences were found just upstream of these transcriptional initiation sites. lacZ fusion analysis confirmed that these three promoters contributed to the expression of mreBCD. On the basis of these findings, the essentiality of the mreB gene was confirmed.
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  • Takahiro ISHIKAWA, Ikuko MASUMOTO, Naofumi IWASA, Hitoshi NISHIKAWA, Y ...
    2006 Volume 70 Issue 11 Pages 2720-2726
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    D-Galacturonic acid reductase, a key enzyme in ascorbate biosynthesis, was purified to homogeneity from Euglena gracilis. The enzyme was a monomer with a molecular mass of 38–39 kDa, as judged by SDS–PAGE and gel filtration. Apparently it utilized NADPH with a Km value of 62.5±4.5 μM and uronic acids, such as D-galacturonic acid (Km=3.79±0.5 mM) and D-glucuronic acid (Km=4.67±0.6 mM). It failed to catalyze the reverse reaction with L-galactonic acid and NADP+. The optimal pH for the reduction of D-galacturonic acid was 7.2. The enzyme was activated 45.6% by 0.1 mM H2O2, suggesting that enzyme activity is regulated by cellular redox status. No feedback regulation of the enzyme activity by L-galactono-1,4-lactone or ascorbate was observed. N-terminal amino acid sequence analysis revealed that the enzyme is closely related to the malate dehydrogenase families.
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  • Qi ZHANG, Gang BAI, Wenbo YANG, Haiyan LI, Huilong XIONG
    2006 Volume 70 Issue 11 Pages 2727-2732
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    The pine wilt disease caused by Bursaphelenchus xylophilus (BX), also known as the pine wood nematode (PWN), is the most devastating disease of pine trees. In this work, a high molecular weight B. xylophilus cellulase antigen (BXCa) was purified from total homogenates of nematodes. BXCa was found to be able to hydrolyze carboxymethyl cellulose (CMC) efficiently (155.65 U/mg) and to have an approximate molecular mass of 58.9 kDa. We harvested anti-BXCa antibodies and performed immunocytochemical assays, which revealed the localization of cellulase pools in the esophageal gland cells of the PWN. It was also discovered that cellulase was secreted from the stylet and was used to hydrolyze cellulose to facilitate the PWN entering host cells. These results are consistent with other plant parasitical nematodes. Interestingly, strong fluorescence signals from cellulase staining were observed in tracheid cells in naturally infected pine wood, in addition to ray cells and the resin canal zone. These results strongly suggest that the cellulase released by the PWN is one of the pathogenic substances of pine wilt disease and is responsible for the development of the early symptoms of the disease.
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  • Yuichi OBA, Kiichi TANAKA, Satoshi INOUYE
    2006 Volume 70 Issue 11 Pages 2739-2744
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    Firefly luciferase and fatty acyl-CoA synthetase are members of the acyl-CoA synthetase super family, which consists of a large N-terminal domain and a small C-terminal domain. Previously we found that firefly luciferase has fatty acyl-CoA synthetic activity, and also identified that the homolog of firefly luciferase in Drosophila melanogaster (CG6178) is a fatty acyl-CoA synthetase and is not a luciferase. In this study, we constructed chimeric proteins by exchanging the domain between Photinus pyralis luciferase (PpLase) and Drosophila CG6178, and determined luminescence and fatty acyl-CoA synthetic activities. A chimeric protein with the N-terminal domain of PpLase and the C-terminal domain of CG6178 (Pp/Dm) had luminescence activity, showing approximately 4% of the activity of wild-type luciferase. The Pp/Dm protein also had fatty acyl-CoA synthetic activity and the substrate specificity was similar to PpLase. In contrast, a chimeric protein with the N-terminal domain of CG6178 and the C-terminal of PpLase (Dm/Pp) had only fatty acyl-CoA synthetase activity, and the substrate specificity was similar to CG6178. These results suggest that the N-terminal domain of firefly luciferase is essential for substrate recognition, and that the C-terminal domain is indispensable but not specialized for the luminescence reaction.
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  • Hitomi ICHINOSE, Toshihisa KOTAKE, Yoichi TSUMURAYA, Satoshi KANEKO
    2006 Volume 70 Issue 11 Pages 2745-2750
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    A gene belonging to glycoside hydrolase family 43 (GH43) was isolated from Streptomyces avermitilis NBRC14893. The gene encodes a modular protein consisting of N-terminal GH43 module and a family 13 carbohydrate-binding module at the C-terminus. The gene corresponding to the GH43 module was expressed in Escherichia coli, and the gene product was characterized. The recombinant enzyme specifically hydrolyzed only β-1,3-linkage of two D-galactosyl residues at non-reducing ends of the substrates. The analysis of the hydrolysis products indicated that the enzyme produced galactose from β-1,3-D-galactan in an exo-acting manner. When the enzyme catalyze hydrolysis of the arabinogalactan-protein, the enzyme produced oligosaccharides together with galactose, suggesting that the enzyme is able to accommodate β-1,6-linked D-galactosyl side chains. These properties are the same as the other previously reported exo-β-1,3-D-galactanases. Therefore, we concluded the isolated gene certainly encodes an exo-β-1,3-D-galactanase. This is the first report of exo-β-1,3-D-galactanase from actinomycetes.
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Biochemistry & Molecular Biology Notes
  • Lin LIN, Tokumitsu WAKABAYASHI, Tomohiro OIKAWA, Tsutomu SATO, Tarou O ...
    2006 Volume 70 Issue 11 Pages 2754-2758
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    Upon presentation of two distinct chemoattractants such as sodium acetate and diacetyl simultaneously, the nematode Caenorhabditis elegans was preferentially attracted by one of these chemoattractants. We isolated two mutants having altered preference of chemotaxis behavior toward simultaneous presentation of sodium acetate and diacetyl. The chep-1(qr1) (CHEmosensory Preference) mutant preferred sodium acetate to diacetyl, while the chep-2(qr2) mutant preferred diacetyl to sodium acetate in simultaneous presentation of these chemoattractants. The chemotaxis behavior of chep-2(qr2) mutant in simultaneous presentation suggests a function of chep-2 gene products within the chemosensory informational integration pathway as well as in the chemosensory pathway.
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  • Masaru SATO, Kohtaro KIRIMURA, Kuniki KINO
    2006 Volume 70 Issue 11 Pages 2790-2792
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    D-Alanine-D-alanine ligase (Ddl) and its mutants maintain the biosynthesis of peptidoglycan, and the substrate specificity of Ddls partially affects the resistance mechanism of vancomycin-resistant enterococci. Through investigation of Ddls, Ddl from Thermotoga maritima ATCC 43589 showed novel characteristics, vis. thermostability up to 90 °C and broad substrate specificity toward 15 D-amino acids, particularly D-alanine, D-cysteine, and D-serine, in that order.
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Food & Nutrition Science Regular Papers
  • Chengxiong XU, Honggu LEE, Bokyun LEE, Jihui WANG, Zhongshan HONG, Tae ...
    2006 Volume 70 Issue 11 Pages 2589-2597
    Published: November 23, 2006
    Released: November 23, 2006
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    The effects were observed of feeding a high-temperature-micro-time (HTMT)-treated diet of high-quality extruded soybean (ESB) on trans-10, cis-12 conjugated linoleic acid (CLA) incorporation in intra-muscular fat and on the lipid metabolism of twelve Holstein steers. The animals were randomly allocated to three groups, the control group being fed on a normal diet, and the other two groups being fed on a diet containing high-quality ESB with or without the HTMT treatment. The experimental period was four months. The content of total CLA in both the HTMT and non-HTMT-treated diets was higher than that in the control diet (P<0.05). The concentration of trans-10, cis-12 CLA was significantly higher in the HTMT-treated diet than in the non-treated diets at P<0.05, and the HTMT-treatment decreased the intra-muscular fat content (P<0.05). The expression of fatty acid synthase (FAS) and the plasma insulin-like growth factor-1 (IGF-1) level in the HTMT-treated group were lower than those in the control group (P<0.05). Lipoprotein lipase (LPL) mRNA level in the adipose tissue was lower in the non-HTMT-treated group than in the control (P<0.05). These results show that the HTMT treatment increased the level of trans-10, cis-12 CLA in the intra-muscular fat. This increased level of trans-10, cis-12 CLA may inhibit lipogenesis in the intra-muscular fat of Holstein steers.
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  • Zinna Marie PULVERA, Keisuke KITAMURA, Makita HAJIKA, Kazuko SHIMADA, ...
    2006 Volume 70 Issue 11 Pages 2598-2603
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    The oxylipin metabolism was analyzed in soybean homogenates containing different sets of lipoxygenase isozymes (L-1, -2, and -3); namely, Suzuyutaka (containing L-1, -2, and -3), Yumeyutaka (containing only L-1), Kanto102 (containing L-2), Kyushu119 (containing L-3), and Ichihime (lacking all three isozymes). The amount of oxidized fatty acids in the esterified form was higher than that in the free form with every cultivar. Kanto102 formed the highest amount of oxidized lipids, and Yumeyutaka and Ichihime formed the lowest. With Kanto102 and Kyushu119, high amounts of keto fatty acids were formed, while they were undetectable with Yumeyutaka and Ichihime. Due to the lack of lipoxygenases in Ichihime, an accumulation of free fatty acids was expected; however, their amount in Yumeyutaka was significantly lower than was expected. It is suggested that a pathway existed to form C6-volatiles through hydroperoxides in the esterified form.
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  • Marina CARBONARO
    2006 Volume 70 Issue 11 Pages 2620-2626
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    7S globulins were extracted from common bean (Phaseolus vulgaris L.) seeds and characterized. SDS–PAGE showed major bands corresponding to the phaseolin subunits (43–53 kDa). An amino acid analysis indicated that, in spite of the limited amounts of sulphur amino acids and tryptophan, the globulins contained very high levels of essential amino acids. The protein solubility profiles of native and denatured (120 °C for 20 min) 7S globulins in water and in 0.5 M NaCl showed that NaCl had a limited effect on increasing the solubility of either the native or denatured proteins. The in vivo small intestinal digestibility of the 7S globulins was 90%, this being decreased to 86% after a thermal treatment. Fourier transform infrared spectroscopy revealed a high content of β-sheet and β-turn structures, together with a contribution at 1687 cm−1 that was assigned to intramolecular β-sheets. These features are diagnostic of a high propensity to irreversible aggregation that may be related to an adverse effect on the protein quality.
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  • Naoki TAKAISHI, Hideo SATSU, Makoto SHIMIZU
    2006 Volume 70 Issue 11 Pages 2703-2711
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    Some of the non-ionic surfactants used in pharmaceutical formulations inhibit P-glycoprotein (P-gp), the multi-drug transporter. The effect of such food emulsifiers as polyglycerol esters (PGE) and sugar esters (SE) of fatty acids on the P-gp activity was studied by using human intestinal Caco-2 cells. The cellular accumulation of [3H]-daunomycin, a P-gp substrate, was markedly enhanced by PGE and SE. This accumulation-enhancing activity varied among the emulsifiers, but was correlated with their surface activity. The uptake of soluble nutrients such as amino acids was only slightly reduced by PGE and SE. These results suggest that these emulsifiers specifically inhibited P-gp. When the basal-to-apical transport of daunomycin across the Caco-2 monolayers was measured, however, the emulsifiers did not decrease the efflux of daunomycin to the apical chamber. The enhanced accumulation of daunomycin would therefore not have been due to P-gp inhibition, but instead to the increased daunomycin permeability of cell membranes caused by the emulsifiers.
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  • Yun Chun LIU, Keita SATOH, Yasushi HASEGAWA
    2006 Volume 70 Issue 11 Pages 2733-2738
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    Previously we found that the organic components in scallop shell promote lipolysis in differentiated 3T3-L1 and C3H10T1/2 adipocyte cells, and that incorporating scallop shell powder into the diet of rats reduced the amount of white adipose tissue. In this study, we used RT-PCR to investigate the effect of ingesting scallop shell powder on the gene expression profile of uncoupling proteins (UCPs) regulating energy metabolism in rats.
    Feeding of scallop shell powder increased mRNA levels of UCP1 and UCP2 in white adipose tissue. By contrast, scallop shell powder had no effect on the expression of UCP1 in brown adipose tissue, although the expression level of UCP2 mRNA decreased significantly. These results suggest that feeding scallop shell powder increases gene expression of UCP1 that may regulate energy metabolism in white adipose tissue, resulting in the observed reduction in weight of white adipose tissue.
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Food & Nutrition Science Notes
Food & Nutrition Science Communication
  • Yoshimasa SUGIURA, Kohji MATSUDA, Yasuhiro YAMADA, Masashi NISHIKAWA, ...
    2006 Volume 70 Issue 11 Pages 2807-2811
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    Eisenia arborea is an edible brown alga occasionally used as a folk medicine in gynecopathy in Japan. A new phlorotannin was isolated from the alga during our search for naturally occurring anti-allergic compounds from edible algae guided by the inhibitory effect on histamine release from rat basophile leukemia (RBL)-2H3 cells. The phlorotannin was called “phlorofucofuroeckol-B.” Its structure was determined by spectral analysis and chemical conversion. This paper describes the isolation, structure elucidation, and inhibitory effect of phlorofucofuroeckol-B on histamine release.
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Microbiology & Fermentation Technology Regular Papers
  • Jun-ichi NIKAWA, Masako YATA, Miki MOTOMURA, Nobutaka MIYOSHI, Tsuyosh ...
    2006 Volume 70 Issue 11 Pages 2604-2612
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
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    Yeast Ino2p-Ino4p heterodimeric complex is well known as a transcriptional activator for the genes regulated by inositol and choline, such as the INO1 gene. Apl2p is a large subunit of the yeast adaptin complex, an adaptor complex required for the clathrin coat to bind to the membrane. We found that Ino2p, Ino4p, and Apl2p form a ternary complex. This interaction was initially observed in a yeast two-hybrid study and subsequently verified by co-immunoprecipitation. Ino2p and Ino4p bind to Apl2p in the same region of Apl2p, viz., at the middle part and the C-terminal part. Ino2p and Ino4p bind to Apl2p independently, but more strongly when both are present. Furthermore, a disruption of APL2 together with INO2 or INO4 rendered yeast cells sensitive to oxidative stress. INO2-APL2 double disruptants also showed growth inability in non-fermentable carbon sources, such as glycerol. These results indicate a genetic interaction between APL2, INO2 and INO4 and uncovere novel functions of the Ino2p-Ino4p-Apl2p complex in yeast.
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  • Shun’ichi ISHII, Hajime UNNO, Shunsuke MIYATA, Katsutoshi HORI
    2006 Volume 70 Issue 11 Pages 2635-2640
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
    JOURNALS FREE ACCESS
    A toluene-degrading bacterium, Acinetobacter sp. Tol 5, shows noteworthy adhesiveness mediated by two types of cell appendages. In this study, we obtained a less-adhesive mutant, T1, which lost both types of appendages, and investigated how the cell appendages affect the adhesion properties of this useful bacterium for environmental technology. Wild-type cells attained irreversible adhesion to polyurethane carriers within 30 s, while adhesion of T1 cells was still reversible at that time. While T1 showed decreased adhesion with decreasing ionic strength and did not adhere at all at 0.015 mM, adhesion of the wild type was fully independent of ionic strength. Acinetobacter sp. Tol 5 was also found to be not motile. Our results suggest that through the long distant interaction mediated by the appendages between the cells and surfaces, Tol 5 cells can attain irreversible adhesion very quickly without approaching the vicinity of the substratum.
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  • Hiromi NISHIDA
    2006 Volume 70 Issue 11 Pages 2646-2652
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
    JOURNALS FREE ACCESS
    Supplementary material
    In this study, I searched for fungal-specific proteins in the genome of the budding yeast Saccharomyces cerevisiae, inferred from a comparison of amino acid sequences. I used the GTOP (Genomes to Protein structures and functions) database of the DDBJ (DNA Data Bank of Japan), which consists of 21 genomes from Archaea, 203 genomes from Bacteria, and 50 genomes from Eucarya (including 18 fungal genomes). Among 5,874 proteins of S. cerevisiae, 1,551 have homologs only in Eucarya, and 504 of the 1,551 have homologs only in fungi. To find fungal-specific proteins, homologs of the homologs have been searched repeatedly. As a result, 132 of the 504 are characterized as fungal-specific proteins. The genes encoding the 132 fungal-specific proteins are not included in the list of essential genes for viability in the S. cerevisiae genome deletion project. Among the 132 proteins, 99 are S. cerevisiae-specific, and no protein that is distributed among 10 or more of the 18 fungal species exists. In addition, most of the fungal-specific proteins are very small and functionally unknown. My results show that the fungal-specific proteins have short evolutionary histories, suggesting that S. cerevisiae produces novel proteins and that ancestral fungi also produced small proteins most of which have disappeared or have been combined with other proteins during fungal evolution.
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  • Chika ORII, Shinji TAKENAKA, Shuichiro MURAKAMI, Kenji AOKI
    2006 Volume 70 Issue 11 Pages 2653-2661
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
    JOURNALS FREE ACCESS
    Bordetella sp. strain 10d metabolizes 4-amino-3-hydroxybenzoic acid via 2-hydroxymuconic 6-semialdehyde. Cell extracts from 4-amino-3-hydroxybenzoate-grown cells showed high NAD+-dependent 2-hydroxymuconic 6-semialdehyde dehydrogenase, 4-oxalocrotonate tautomerase, 4-oxalocrotonate decarboxylase, and 2-oxopent-4-enoate hydratase activities, but no 2-hydroxymuconic 6-semialdehyde hydrolase activity. These enzymes involved in 4-amino-3-hydroxybenzoate metabolism were purified and characterized. When 2-hydroxymuconic 6-semialdehyde was used as substrate in a reaction mixture containing NAD+ and cell extracts from 4-amino-3-hydroxybenzoate-grown cells, 4-oxalocrotonic acid, 2-oxopent-4-enoic acid, and 4-hydroxy-2-oxovaleric acid were identified as intermediates, and pyruvic acid was identified as the final product. A complete pathway for the metabolism of 4-amino-3-hydroxybenzoic acid in strain 10d is proposed. Strain 10d metabolized 2-hydroxymuconic 6-semialdehyde derived from 4-amino-3-hydroxybenzoic acid via a dehydrogenative route, not via a hydrolytic route. This proposed metabolic pathway differs considerably from the modified meta-cleavage pathway of 2-aminophenol and those previously reported for methyl- and chloro-derivatives.
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Microbiology & Fermentation Technology Notes
Microbiology & Fermentation Technology Preliminary Communication
  • Satoshi MITSUHASHI, Mikiro HAYASHI, Junko OHNISHI, Masato IKEDA
    2006 Volume 70 Issue 11 Pages 2803-2806
    Published: November 23, 2006
    Released: November 23, 2006
    [Advance publication] Released: November 07, 2006
    JOURNALS FREE ACCESS
    Genomic analysis of a classically derived L-lysine-producing mutant, Corynebacterium glutamicum B-6, identified a nonsense mutation in the mqo gene, which encodes malate:quinone oxidoreductase (MQO). The effect of mqo disruption on L-lysine production was investigated in a defined L-lysine producer, C. glutamicum AHP-3, showing approximately 18% increased production. To explore the underlying mechanisms of the increase, the mqo-disrupted strain was analyzed from the viewpoints of redox balance, activities of membrane-bound dehydrogenases, and transcriptome. The intracellular [NADH]/[NAD] ratio in the strain remained unchanged. Also, there were no significant differences in the activities of the membrane-bound dehydrogenases examined. However, transcriptome analysis showed that some TCA cycle genes, such as acn, sucC, and sucD, were down-regulated in the strain. These results suggest that the loss of MQO activity down-regulates the flux of the TCA cycle to maintain the redox balance and results in redirection of oxaloacetate into L-lysine biosynthesis.
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