Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 72 , Issue 10
Showing 1-45 articles out of 45 articles from the selected issue
Award Review
  • Kenji WATANABE
    2008 Volume 72 Issue 10 Pages 2491-2506
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    Much effort has been invested in studying how natural products are biosynthesized, and great advances have been made in understanding how these compounds acquire their structural complexity and biological activities. In recent years, significant progress has been made due to the devoted efforts of scientists in this field and to technological advancements. Numerous details, applications, and innovative findings have been elucidated by scientists using biochemical, genetic, and molecular biological approaches. Here I present a comprehensive overview of highly valued biosynthetic proteins, polyketide synthase and nonribosomal peptide synthetase. I begin with “Diels-Alderase” a captivating enzyme that has the ability to catalyze a Diels-Alder reaction valued by chemists for its usefulness in chemical synthesis. A handful of these enzymes have been characterized and chemically authenticated. The most well understood enzyme of this category is macrophomate synthase. Secondly, I focus on the polyketide and nonribosomal peptide biosynthetic pathways and the enzyme assembly for producing its metabolite. Many important natural products are produced by this biosynthetic pathway as secondary metabolites, such as erythromycin, rifamycin, and FK520, as antibiotics and an immunosuppressive, respectively. I conclude with a discussion of nonribosomal peptides and their mechanistic pathways. Special attention will be devoted to de novo production of echinomycin in a heterologous manner, the earliest example of totally engineered biosynthesis of the biologically active form of a nonribosomal peptide host in Escherichia coli.
    Download PDF (578K)
Analytical Chemistry Regular Paper
  • Shinichi TAKAICHI, Takashi MAOKA, Naoshige AKIMOTO, Marvelisa L. CARMO ...
    2008 Volume 72 Issue 10 Pages 2615-2622
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    We isolated a strain of Corynebacterineae from surface seawater from the Inland Sea of Japan. This strain, AIST-1, was determined to be a strain of Gordonia terrae based on its 16S rRNA gene sequence. The colony was red-colored, and the pigments were identified to be carotenoid derivatives. The structures of two major carotenoids were (2′S)-deoxymyxol 1′-glucoside, a dihydroxyl derivative of γ-carotene with 12 conjugated double bonds, and (2′S)-4-ketodeoxymyxol 1′-glucoside. Their glucosyl acyl esters and mycoloyl esters were also identified. While these carotenoid moieties have been found in only a few other bacteria, the carotenoid mycoloyl esters are novel carotenoid derivatives. The type strain of G. terrae NBRC 10016T also contained the same carotenoids, but the composition of the two carotenoid glucosides was low and the total carotenoid content was less than one tenth of that of strain AIST-1.
    Download PDF (152K)
Organic Chemistry Regular Papers
  • Hirosuke SUGAHARA, Tatsuhiko KONDO, Masahiro OKADA, Yasuya IKEDA, Keni ...
    2008 Volume 72 Issue 10 Pages 2521-2525
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    A two-component system (TCS) comprising a histidine kinase (HK) sensor and a response regulator (RR) plays important roles in regulating the virulence of many pathogenic bacteria. We used a new screening method to isolate novel inhibitor Art1 against bacterial sensory HK from an acetone extract of solid cultures of Articulospora sp., an aquatic hypomycete. Art1 inhibited the ATP-dependent autophosphorylation of recombinant glutathione S-transferase-fusion protein SasA, a cyanobacterial HK, with an IC50 value of 9.5 μg/ml.
    Download PDF (108K)
  • Daniela I. BATOVSKA, Dong Hoon KIM, Shinya MITSUHASHI, Yoon Sun CHO, H ...
    2008 Volume 72 Issue 10 Pages 2623-2631
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    Mycophenolic acid (MPA, 1), an inhibitor of IMP-dehydrogenase (IMPDH) and a latent PPARγ agonist, is used as an effective immunosuppressant for clinical transplantation and recently entered clinical trials in advanced multiple myeloma patients. On the other hand, suberoylanilide hydroxamic acid (SAHA), a non-specific histone deacetylase (HDAC) inhibitor, has been approved for treating cutaneous T-cell lymphoma. MPA seemed to bear a cap, a linker, and a weak metal-binding site as a latent inhibitor of HDAC. Therefore, the hydroxamic acid derivatives of mycophenolic acid having an effective metal-binding site, mycophenolic hydroxamic acid (MPHA, 2), 7-O-acetyl mycophenolic acid (7-O-Ac MPHA, 3), and 7-O-lauroyl mycophenolic hydroxamic acid (7-O-L MPHA, 4) were designed and synthesized. All these compounds inhibited histone deacetylase with IC50 values of 1, 0.9 and 0.5 μM, and cell proliferation at concentrations of 2, 1.5 and 1 μM, respectively.
    Download PDF (218K)
  • Ken YOSHIOKA, Izumi TAKAISHI, Kazunari SHIOZAWA, Yukiharu FUKUSHI, Sat ...
    2008 Volume 72 Issue 10 Pages 2632-2639
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    Efficient syntheses of 14H-dinaphtho[1,8-bc:1′,8′-fg]oxocin-14-one (2), 14H-dinaphtho[1,8-bc:1′,2′-f]oxepin-14-one (3), and 2,2′(2H,2′H)-spirobi[naphtho[1,8-bc]furan] (9) are described. The putative structure of 2 has been reported previously, but the synthetic route was not reproducible. 7H-Dibenzo[c,h]xanthen-7-one (4), a known compound, was obtained by a different method. Possible reaction mechanism are proposed.
    Download PDF (144K)
  • Noriaki KOBAYASHI, Hidenobu KUNIYOSHI, Ken ISHIGAMI, Hidenori WATANABE
    2008 Volume 72 Issue 10 Pages 2708-2715
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    Both enantiomers of FF8181-A were synthesized through optical resolution from the known Diels-Alder reaction product in 15 steps. The absolute configuration of the natural product was determined to be 1S,5S,5aS,9aS,9bS.
    Download PDF (143K)
  • Min-Jung CHANG, Tran Manh HUNG, Byung-Sun MIN, Jin-Cheol KIM, Mi Hee W ...
    2008 Volume 72 Issue 10 Pages 2750-2755
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    The objective of the present study was to investigate the beneficial properties lignan compounds obtained from the fruits of Forsythia suspensa (Thunb.) Vahl (Oleaceae) for protecting human high-density lipoprotein (HDL) against lipid peroxidation. The isolated compounds (1–8) inhibited the generation of thiobarbituric acid-reactive substances (TBARS) in a dose-dependent manner with IC50 values from 8.5 to 18.7 μM, since HDL oxidation mediated by catalytic Cu2+. They also exerted an inhibitory effect against thermo-labile radical initiator (AAPH)-induced lipid peroxidation of HDL with IC50 values from 12.1 to 51.1 μM. Compounds 1 and 5 exerted inhibitory effects against the Cu2+-induced lipid peroxidation of HDL, as shown by an extended lag time prolongation at the concentration of 3.0 μM. These results suggest that the antioxidative effects of F. suspensa are due to its lignans and that these constituents may be useful for preventing the oxidation of HDL.
    Download PDF (107K)
Organic Chemistry Notes
Biochemistry & Molecular Biology Regular Papers
  • Hiroyuki NOZAKI, Shinji KURODA, Kunihiko WATANABE, Kenzo YOKOZEKI
    2008 Volume 72 Issue 10 Pages 2580-2588
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    The α-methylserine aldolase gene from Variovorax paradoxus strains AJ110406, NBRC15149, and NBRC15150 was cloned and expressed in Escherichia coli. Formaldehyde release activity from α-methyl-L-serine was detected in the cell-free extract of E.coli expressing the gene from three strains. The recombinant enzyme from V. paradoxus NBRC15150 was purified. The Vmax and Km of the enzyme for the formaldehyde release reaction from α-methyl-L-serine were 1.89 μmol min−1 mg−1 and 1.2 mM respectively. The enzyme was also capable of catalyzing the synthesis of α-methyl-L-serine and α-ethyl-L-serine from L-alanine and L-2-aminobutyric acid respectively, accompanied by hydroxymethyl transfer from formaldehyde. The purified enzyme also catalyzed alanine racemization. It contained 1 mole of pyridoxal 5′-phosphate per mol of the enzyme subunit, and exhibited a specific spectral peak at 429 nm. With L-alanine and L-2-aminobutyric acid as substrates, the specific peak, assumed to be a result of the formation of a quinonoid intermediate, increased at 498 nm and 500 nm respectively.
    Download PDF (246K)
  • Kazuomi SATO, Masayuki MORITA, Chihiro ICHIKAWA, Hideki TAKAHASHI, Mas ...
    2008 Volume 72 Issue 10 Pages 2589-2597
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    We assessed the effects of ATRA and retinol on melanogenesis in murine B16 melanoma cells. In the present study, ATRA and retinol inhibited melanin synthesis in melanoma cells stimulated by α-melanocyte stimulating hormone (α-MSH) or 3-isobutyl-1-methylxanthine (IBMX). To elucidate the target points of ATRA and retinol on melanogenesis, we performed western blotting for melanogenic proteins, such as tyrosinase, tyrosinase-related protein (TRP)-1, and TRP-2. ATRA inhibited the expression of tyrosinase and TRP-1, and retinol inhibited the expression of tyrosinase, in a dose-dependent manner. Neither ATRA nor retinol inhibited TRP-2 expression. There were no differences in melanogenic protein expression between the two stimulants tested, α-MSH and IBMX. Therefore, the depigmenting effect of ATRA and retinol might be due to inhibition of the signaling pathway between cAMP and tyrosinase transcription bound to tyrosinase expression. These results indicate that ATRA and retinol are candidate anti-melanogenic agents that they might be effective in hyperpigmentation disorders.
    Download PDF (158K)
  • Yukinori YABUTA, Takanori MARUTA, Ayana NAKAMURA, Takahiro MIEDA, Kazu ...
    2008 Volume 72 Issue 10 Pages 2598-2607
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    In this study we focused on the effects of light irradiation and the addition of L-galactono-1,4-lactone (L-GalL) on the conversion of exogenous L-GalL to L-ascorbate (AsA) and the total AsA pool size in detached leaves of Arabidopsis plants and transgenic plants expressing the rat L-gulono-1,4-lactone oxidase gene. Increases in the total AsA level in L-GalL-treated leaves depended entirely on light irradiation. Treatment with an inhibitor of photosynthetic electron transport together with L-GalL reduced the increase in total AsA under light. Light, particularly the redox state of photosynthetic electron transport, appeared to play an important role in the regulation of the conversion of L-GalL to AsA in the mitochondria, reflecting the cellular level of AsA in plants.
    Download PDF (140K)
  • Suguru OGURI, Koh AMANO, Hideo NAKASHITA, Yoshiho NAGATA, Yoshie S. MO ...
    2008 Volume 72 Issue 10 Pages 2640-2650
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    A cDNA encoding tomato fruit lectin was cloned from an unripe cherry-tomato fruit cDNA library. The isolated lectin cDNA contained an open reading frame encoding 365 amino acids, including peptides that were sequenced. The deduced sequence consisted of three distinct domains: (i) an N-terminal short extensin-like domain; (ii) a Cys-rich carbohydrate binding domain composed of four almost identical chitin-binding domains; (iii) an internal extensin-like domain of 101 residues containing 15 SerPro4 motifs inserted between the first and second chitin-binding domains. The molecular weight of the lectin was 65,633 and that of the deglycosylated lectin was 32,948, as determined by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). This correlated with the estimated molecular weight of the deduced sequence. Recombinant tomato lectin expressed in Pichia pastoris possessed chitin-binding but not hemagglutinating activity. These findings confirmed that the cDNA encoded tomato lectin.
    Download PDF (1256K)
  • Junichi TSUGE, Hiroko HIRATSUKA, Hisashi KAMIMIYA, Hirofumi NOZAKI, Ya ...
    2008 Volume 72 Issue 10 Pages 2667-2674
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    Seven strains of fungi were isolated from activated sludge and identified as Mucor sp., Geotrichum sp., Trichosporon sp., Candida sp., and Trichoderma sp. by 28S rDNA D2 region sequences analysis. The structures of the main ceramide monosaccharides (CMSs) from these fungi were identified as glucosylceramide (GlcCer) consisting of ceramide moieties of 9-methyl-octadeca-sphingadienine (9-Me d18:2), with 2-hydroxyhexadecanoate (h16:0) (Mucor sp. and Geotrichum sp.), 2-hydroxyoctadecanoate (h18:0) (Trichosporon sp. and Candida sp.), and 2-hydroxyoctadecenoate (h18:1) (Trichoderma sp.). Seasonal changes in glycosphingolipids in activated sludge suggest the possibility that microbial flora in activated sludge changes with the seasons, and that fungi adaptable to low temperatures dominate in the cold period, resulting in the maintenance of stable effluent quality. Mucor sp., Geotrichum sp., and Candida sp. satisfactorily reduced the BOD of synthetic sewage at 10 °C. These results indicate that fungi in activated sludge can contribute to wastewater treatment in cold conditions.
    Download PDF (213K)
  • Aya HAMAGUCHI, Takafumi YAMASHINO, Nobuya KOIZUMI, Takatoshi KIBA, Mik ...
    2008 Volume 72 Issue 10 Pages 2687-2696
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    More than 1,600 genes encoding transcription factors have been identified in the Arabidopsis genome sequence, but their physiological functions are not yet fully understood. In this study, a small subfamily of single-MYB transcription factor genes, designated RSM1, RSM2, RSM3 and RSM4 (RADIALIS-LIKE SANT/MYB 1-4), was characterized. Here, we mainly examined the RSM1 gene, and found that it appears to play a role in close connection with the HLS1 (HOOKLESS 1) gene during early morphogenesis. Etiolated seedlings overexpressing RSM1 showed several phenotypes similar to those of hls1-1, viz., lack of apical hooks with short hypocotyls, and a defect in gravitropism. Furthermore, both RSM1-ox and hls1-1 seedlings were hypersensitive to red light during early photomorphogenesis, displaying shorter hypocotyls than wild-type seedlings. The histochemical profile of the DR5::GUS auxin-reporter in the RMS1-ox seedlings was considerably different from that in the wild-type seedlings. These results are discussed in the context of the possibility that RSM1 is implicated in HLS1-mediated auxin signaling, which is responsible for regulation of the early photomorphogenesis of Arabidopsis thaliana.
    Download PDF (354K)
  • Hirotaka INOUE, Naomi YUASA-HASHIMOTO, Michio SUZUKI, Hiromichi NAGASA ...
    2008 Volume 72 Issue 10 Pages 2697-2707
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    A novel matrix protein named calcification-associated soluble protein-2 (Casp-2) was isolated from the acetic acid-soluble fraction of the exoskeleton of the crayfish Procambarus clarkii, and its primary structure was determined by a combination of peptide sequencing, mass spectral analysis, and cDNA cloning. Casp-2 consists of 117 amino acid residues and has a chitin-binding consensus sequence, the so-called Rebers-Riddiford (R-R) consensus sequence. Casp-2 exhibited an inhibitory activity on calcium carbonate precipitation from its supersaturated solution in vitro, suggesting association with calcification of the exoskeleton. Reverse transcription PCR and Northern blot analyses indicated that the Casp-2 gene was expressed only at the epidermis throughout the molting stages, and most strongly at the late pre-molt stage. Recombinant Casp-2 showed weak affinity to chitin in spite of having the R-R consensus sequence. These results indicate that Casp-2 interacts loosely with chitin fibrils and regulates calcification in the cuticle.
    Download PDF (700K)
  • Kazunobu MATSUSHITA, Yoshiki KOBAYASHI, Mitsuhiro MIZUGUCHI, Hirohide ...
    2008 Volume 72 Issue 10 Pages 2723-2731
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    Quinoprotein alcohol dehydrogenase (ADH) of acetic acid bacteria is a membrane-bound enzyme that functions as the primary dehydrogenase in the ethanol oxidase respiratory chain. It consists of three subunits and has a pyrroloquinoline quinone (PQQ) in the active site and four heme c moieties as electron transfer mediators. Of these, three heme c sites and a further site have been found to be involved in ubiquinone (Q) reduction and ubiquinol (QH2) oxidation respectively (Matsushita et al., Biochim. Biophys. Acta, 1409, 154–164 (1999)). In this study, it was found that ADH solubilized and purified with dodecyl maltoside, but not with Triton X-100, had a tightly bound Q, and thus two different ADHs, one having the tightly bound Q (Q-bound ADH) and Q-free ADH, could be obtained. The Q-binding sites of both the ADHs were characterized using specific inhibitors, a substituted phenol PC16 (a Q analog inhibitor) and antimycin A. Based on the inhibition kinetics of Q2 reductase and ubiquinol-2 (Q2H2) oxidase activities, it was suggested that there are one and two PC16-binding sites in Q-bound ADH and Q-free ADH respectively. On the other hand, with antimycin A, only one binding site was found for Q2 reductase and Q2H2 oxidase activities, irrespective of the presence of bound Q. These results suggest that ADH has a high-affinity Q binding site (QH) besides low-affinity Q reduction and QH2 oxidation sites, and that the bound Q in the QH site is involved in the electron transfer between heme c moieties and bulk Q or QH2 in the low-affinity sites.
    Download PDF (157K)
  • Hiroko OTA, Hideto TAMEZANE, Yoshie SASANO, Eisaku HOKAZONO, Yuko YASU ...
    2008 Volume 72 Issue 10 Pages 2732-2738
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    Ethanolamine oxidase was screened with the aim of using it to establish a novel enzymatic phosphatidylethanolamine assay. Ethanolamine oxidase activity was detected in the crude extract of Arthrobacter sp., and the enzyme was purified more than 15-fold in three steps with a 54% yield. SDS–PAGE revealed the presence of only one band, which migrated, with an apparent molecular mass of 70 kDa. Biochemical characterization of the enzyme showed phenylethylamine to be the preferred substrate, with the highest kcat/Km value. The primary structure, determined by sequencing the cloned gene, showed a high degree of identity to Cu-containing phenylethylamine oxidase (64%). When heterologously overexpressed in Escherichia coli, the enzyme exhibited only a trace of amine oxidase activity, but high levels of activity emerged after exposure to Cu2+, as is typical of recombinant copper amine oxidases. Preliminary application of this enzyme coupled with phospholipase D for determination of phosphatidylethanolamine is also described. This is the first enzymatic method for the measurement of phosphatidylethanolamine.
    Download PDF (593K)
  • Isao MIYAZAKI, Siro SIMIZU, Harumi ICHIMIYA, Makoto KAWATANI, Hiroyuki ...
    2008 Volume 72 Issue 10 Pages 2739-2749
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    The identification of specific interactions between small molecules and human proteins of interest is a fundamental step in chemical biology and drug development. Here we describe an efficient method to obtain novel binding ligands of human proteins by a chemical array approach. Our method includes large-scale ligand screening with two libraries, proteins and chemicals, the use of cell lysates that express proteins of interest fused with red fluorescent protein, and high-throughput screening by merged display analysis, which removes false positive signals from array experiments. Using our systematic platform, we detected novel inhibitors of carbonic anhydrase II. It is suggested that our systematic platform is a rapid and robust approach to screen novel ligands for human proteins of interest.
    Download PDF (250K)
Biochemistry & Molecular Biology Notes
Food & Nutrition Science Regular Papers
  • Sang-Suk KIM, Jong Seok BAIK, Tae-Heon OH, Weon-Jong YOON, Nam Ho LEE, ...
    2008 Volume 72 Issue 10 Pages 2507-2513
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    This study was designed to analyze the chemical composition of Citrus obovoides (Geumgamja) and Citrus natsudaidai (Cheonyahagyul) oils and to test their biological activities. These citrus essential oils were obtained by steam distillation of fruits collected from Jeju Island, Korea, and were analyzed using gas chromatograph (GC)-flame ionization detectors (FID) and GC-MS. Limonene and γ-terpinene were the major components of the two citrus species. To evaluate in vitro anti-acne activity, they were tested against Propionibacterium acnes and Staphylococcus epidermidis, which are involved in acne. The Geumgamja and Cheonyahagyul oils exhibited antibacterial activity against both P. acnes and S. epidermidis. Their effects on DPPH radical scavenging, superoxide anion radical scavenging, and nitric oxide radical were also assessed. Cheonyahagyul and Geumgamja exhibited only superoxide anion radical-scavenging activity. To assess their potential usefulness in future cosmetic product applications, the cytotoxic effects of the two oils were determined by colorimetric MTT assays using two animal cell lines: normal human fibroblasts and HaCaT cells. They exhibited low cytotoxicity at 0.1 μl/ml in both cell lines. In addition, they reduced P. acnes-induced secretion of interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF-α) in THP-1 cells, an indication of anti-inflammatory effects. Therefore, based on these results, we suggest that Geumgamja and Cheonyahagyul essential oils are attractive acne-mitigating candidates for topical application.
    Download PDF (193K)
  • Jinn-Tsyy LAI, Hsun-Lang FANG, Wen-Tsong HSIEH, Wen-Chuan LIN
    2008 Volume 72 Issue 10 Pages 2514-2520
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    The protective effect of a fermented substance from Saccharomyces cerevisiae (FSSC) on liver injury caused by acetaminophen (AAP) was studied in mice. Mice were pretreated with FSSC (0.5–2.0 g/kg, p.o.) for 4 d, and on the fourth day, the mice received an overdose of AAP (500 mg/kg, i.p.). Subsequently, they were sacrificed at 7 h, and blood was drawn from the abdominal vein and liver samples were collected. Histological and biochemical examinations revealed that the administration of AAP caused liver injury in the mice, including increases in plasma alanine aminotransferase and asparate aminotransferase activities and decreases in the hepatic reduced form of glutathione (GSH) content and antioxidant enzyme activities. Prior to AAP treatment, the mice pretreated with FSSC showed significantly reduced levels of alanine aminotransferase (ALT) and aspirate aminotransferase (AST) activity. Liver histology in the FSSC-pretreated mice was significant. In these mice, pretreatment with FSSC also served to reduce hepatic GSH depletion and the inhibition of antioxidant enzyme activity caused by AAP overdose. In conclusion, oral administration of FSSC significantly reduced AAP-induced hepatic injury in the mice.
    Download PDF (186K)
  • Masahiko ITO, Kenji OHISHI, Yasuto YOSHIDA, Takekazu OKUMURA, Tadashi ...
    2008 Volume 72 Issue 10 Pages 2543-2547
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    We investigated the preventive effect of Streptococcus thermophilus YIT 2001, a lactic acid bacterum having high antioxidative activity, on acute colitis induced by 2.5% dextran sulfate sodium in mice, and compared the effect with that of S. thermophilus YIT 2084 which has lower antioxidative activity. Feeding S. thermophilus YIT 2001 decreased the disease activity index and level of lipid peroxide (the thiobarbituric acid reactive substance content) in the colonic mucosa. The hematocrit and hemoglobin concentrations in the blood of S. thermophilus YIT 2001-fed mice were higher than those of the control mice. S. thermophilus YIT 2084 had no significant effect on these parameters. The results suggest that the antioxidative activity of S. thermophilus YIT 2001 was involved in the improving effect on colitis.
    Download PDF (80K)
  • Phyllis S. Y. TAM, Rumi SAWADA, Yan CUI, Akiyo MATSUMOTO, Yoko FUJIWAR ...
    2008 Volume 72 Issue 10 Pages 2548-2554
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    To investigate the metabolism and distribution of docosapentaenoic acid (22:5n-6, DPA) in the liver and testis of growing rats, 22:5n-6 was administered to their dams. Newborn rats with a low hepatic arachidonic acid (20:4n-6, AA) level were generated by administrating a diet rich in docosahexaenoic acid (22:6n-3, DHA) but n-6 fatty acid (FA) free to pregnant dams. After parturition, 22:5n-6 or linoleic acid (18:2n-6, LA) was administered with a high level of 22:6n-3 to the dams until weaning. At weaning, the hepatic 20:4n-6 level was significantly highest in the DPA-DHA but not LA-DHA diet-fed animals. The hepatic delta-6 desaturase (D6D) mRNA abundance was significantly lower in both the LA-DHA and DPA-DHA diet-fed animals, connoted with the 20:4n-6 content recovered by 22:5n-6 that did not involve D6D and supporting the occurrence of retroconversion in the liver of the growing rats. The low D6D level in the 3-week-old testis was not in proportion to the elevated 22:5n-6 level, implying that early testicular 22:5n-6 accumulation might require supply from the circulation system.
    Download PDF (95K)
  • Takeshi MATSUBARA, Naohito AOKI, Tsutomu HONJOH, Koko MIZUMACHI, Jun-i ...
    2008 Volume 72 Issue 10 Pages 2555-2565
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    Intestinal absorption of food proteins is well known, whereas its physiological significance remains to be investigated. Various amounts (1, 10 and 50 mg) of ovalbumin were orally administered to mice and the blood kinetics were subsequently analyzed by two-site ELISA. The blood ovalbumin concentration consistently reached its maximum (7–90 ng/ml) about 20 min after the oral administration and then gradually decreased in a dose-dependent manner. Only intact (45 kDa) and truncated (40 kDa) ovalbumins were always detected in the blood independently of the administration site, intra-stomach or intra-intestine, while various fragments of the protein were observed in the gastrointestinal lumen after the oral administration. Recognition by a specific monoclonal antibody and an acidic shift of its pI value suggested that the 40-kDa truncated ovalbumin was produced by intracellular limited proteolysis at its C-terminus. Such stable absorption and blood kinetics of undigested ovalbumin in normal mice suggest some sort of physiological significance for the intestinal uptake of intact food proteins.
    Download PDF (291K)
  • Takeshi CHIJIMATSU, Iwao TATSUGUCHI, Kazuaki ABE, Hiroaki ODA, Satoshi ...
    2008 Volume 72 Issue 10 Pages 2566-2571
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    The effect of a freshwater clam (Corbicula fluminea) extract (FCE) on cholesterol metabolism in rats fed on a high-cholesterol diet was investigated. When rats were fed various amounts of FCE in addition to the high-cholesterol diet for 2 wk, the serum and hepatic cholesterol levels were gradually reduced in a dose-dependent manner, as compared with the control group. The excretion of neutral sterols and bile acids into the feces was increased by feeding FCE. Several phytosterols were detected in the feces of rats fed on the FCE-containing diet. In addition, substantial amounts of phytosterols were found in FCE. Cholesterol 7α-hydroxylase (CYP7A1) mRNA in the liver of the rats fed on the FCE-containing diets was higher than that of rats fed on the high-cholesterol diets without FCE. These results may suggest that enhanced cholesterol degradation and the excretion of neutral sterols and bile acids contributed to the hypocholesterolemic effect of FCE observed in the hypercholesterolemic rats fed on the high-cholesterol diet.
    Download PDF (89K)
  • Saki FUJIMOTO, Kazuki MOCHIZUKI, Masaya SHIMADA, Yuki MURAYAMA, Toshin ...
    2008 Volume 72 Issue 10 Pages 2572-2579
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    A high-fat diet is thought to enhance inflammation in various tissues by increasing insulin resistance. In this study, we determined the mRNA levels of inflammatory cytokines in leukocyte-derived cells in the blood of rats with high-fat-diet-induced insulin resistance. Feeding rats a high-fat diet for 77 d induced moderate insulin resistance, which was determined by increased plasma glucose and insulin concentrations, following an oral glucose tolerance test. The interleukin (IL)-1β mRNA level was higher in the insulin-resistant rats than in control rats at the fasting stage, whereas the tumor necrosis factor (TNF)-α mRNA level was greatly elevated at 180 min after glucose administration in the insulin-resistant rats. The results suggest that feeding rats a high-fat diet enhances the expression of fasting IL-1β and postprandial TNF-α genes in leukocyte-derived cells.
    Download PDF (178K)
  • Yusaku IWASAKI, Manabu TANABE, Kenji KOBATA, Tatsuo WATANABE
    2008 Volume 72 Issue 10 Pages 2608-2614
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    Thermosensitive transient receptor potential (TRP) channels, especially TRPV1 and TRPA1, are activated by the pungent compounds present in spices. TRPV1 activation by the intake of capsaicin, the irritant in hot pepper, induces adrenaline secretion and increases energy consumption. TRPV1 is mainly expressed in the sensory neurons and coexpressed with TRPA1 at a high frequency. However, the mechanism underlying adrenaline secretion by TRPA1 agonists such as allyl isothiocyanate (AITC) and cinnamaldehyde (CNA), the pungent ingredients in mustard and cinnamon, is not known. We examined whether AITC and CNA could induce adrenaline secretion in anesthetized rats. An intravenous injection of AITC or CNA (10 mg/kg) increased adrenaline secretion. These responses disappeared completely in capsaicin-treated rats with an impaired sensory nerve function. Moreover, pretreatment with cholinergic blockers (hexamethonium and atropine) attenuated the AITC- or CNA-induced adrenaline secretion. These results suggest that TRPA1 agonists activate the sensory nerves and induce adrenaline secretion via the central nervous system.
    Download PDF (152K)
  • Kenji MATSUMOTO, Shin-ichiro YOKOYAMA, Nobuki GATO
    2008 Volume 72 Issue 10 Pages 2651-2659
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    We investigated the hypolipidemic effects of young persimmon fruit (YP) on apolipoprotein E-deficient C57BL/6.KOR-ApoEshl mice. These mice exhibited higher plasma cholesterols, except for high-density lipoprotein (HDL), and lower plasma HDL cholesterol than C57BL/6.Cr mice that had the same genetic background as the C57BL/6.KOR-ApoEshl mice. Male C57BL/6.KOR-ApoEshl mice (n=5) were fed a diet supplemented with dry YP, Hachiya-kaki, at a concentration of 5% (w/w) for 10 weeks. YP treatment significantly lowered plasma chylomicron, very low-density lipoprotein (VLDL) and low-density lipoprotein (LDL) cholesterols, and triglyceride, and this response was accompanied by an elevation of fecal bile acid excretion. In the liver, sterol regulatory element binding protein-2 gene expression was significantly higher in mice fed YP, while the mRNA and protein levels of the LDL receptor did not change. These results indicate that acceleration of fecal bile acid excretion is a major mechanism of the hypolipidemic effect induced by YP in C57BL/6.KOR-ApoEshl mice.
    Download PDF (298K)
  • Masako ABE, Yoshio OZAWA, Yasujiro MORIMITSU, Kikue KUBOTA
    2008 Volume 72 Issue 10 Pages 2681-2686
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    We isolated a novel pungent principle from the flower buds of myoga. Based on an interpretation of the HR-MS, EI-MS, IR, UV, and NMR data, this compound was (8βH)-14,17-cyclolabda-12,14(17)-diene-15,16-dial (mioganal, 1). We determined the threshold value of mioganal to be 5.6×10−5 g/ml, which is about eight times greater than that of 8β(17)-epoxy-12(E)labdene-15,16-dial (miogadial), the main pungent principle in the flower buds of myoga. In addition, we examined the content of mioganal in different parts of different varieties. Mioganal is mainly distributed in the leaves of both natsumyoga and akimyoga varieties at 1.60 mg/100 g fresh weight on average, its amount being three times higher than that in the flower buds.
    Download PDF (180K)
  • Tsutomu HAYAKAWA, Aditya KULKARNI, Yukimasa TERADA, Takashi MAOKA, Hid ...
    2008 Volume 72 Issue 10 Pages 2716-2722
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    The in vitro reactivities of astaxanthin toward peroxynitrite were investigated and the reaction products after scavenging with peroxynitrite were analyzed in order to determine the complete mechanism of this reaction. A series of carotenoids, 13-apo-astaxanthinone (1), 12′-apo-15′-nitroastaxanthinal (2), 12′-apo-astaxanthinal (3), 10′-apo-astaxanthinal (4), 9-cis-14′-s-cis-15′-nitroastaxanthin (5), 14′-s-cis-15′-nitroastaxanthin (6), 13-cis-14′-s-cis-15′-nitroastaxanthin (7), 10′-s-cis-11′-cis-11′-nitroastaxanthin (8), 13,15,13′-tri-cis-15′-nitroastaxanthin (9), 9-cis-astaxanthin (10), and 13-cis-astaxanthin (11), were isolated from the reaction products of carotenoids with peroxynitrite. Our previous studies achieved for the first time the isolation of nitro derivatives from the reaction of astaxanthin with peroxynitrite. Here we identify the major remaining reaction products of this reaction and investigate the stabilities of the nitro astaxanthins.
    Download PDF (131K)
Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Akiko OKAMOTO-KAINUMA, Yasunori EHATA, Manami IKEDA, Takemasa OSONO, M ...
    2008 Volume 72 Issue 10 Pages 2526-2534
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    The bacterium Acetobacter pasteurianus can ferment acetic acid, a process that proceeds at the risk of oxidative stress. To understand the stress response, we investigated catalase and OxyR in A. pasteurianus NBRC3283. This strain expresses only a KatE homolog as catalase, which is monofunctional and growth dependent. Disruption of the oxyR gene increased KatE activity, but both the katE and oxyR mutant strains showed greater sensitivity to hydrogen peroxide as compared to the parental strain. These mutant strains showed growth similar to the parental strain in the ethanol oxidizing phase, but their growth was delayed when cultured in the presence of acetic acid and of glycerol and during the acetic acid peroxidation phase. The results suggest that A. pasteurianus cells show different oxidative stress responses between the metabolism via the membrane oxidizing pathway and that via the general aerobic pathway during acetic acid fermentation.
    Download PDF (356K)
  • Kohei ISHIKAWA, Yoshiya GUNJI, Hisashi YASUEDA, Kozo ASANO
    2008 Volume 72 Issue 10 Pages 2535-2542
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    To improve the amino acid production by metabolic engineering, eliminating the pathway bottleneck is known to be very effective. The metabolic response of Methylophilus methylotrophus upon the addition of glucose and of pyruvate was investigated in batch cultivation. We found that the supply of pyruvate is a bottleneck in L-lysine production in M. methylotrophus from methanol as carbon source. M. methylotrophus has a ribulose monophosphate (RuMP) pathway for methanol assimilation, and consequently synthesized fructose-6-phosphate is metabolized to pyruvate via the Entner-Doudoroff (ED) pathway, and the ED pathway is thought to be the main pathway for pyruvate supply. An L-lysine producer of M. methylotrophus with an enhanced ED pathway was constructed by the introduction of the E. coli edd-eda operon encoding the enzyme involving the ED pathway. In this strain, the overall enzymatic activity of ED pathway, which is estimated by measuring the activities of 6-phosphogluconate dehydrogenase plus 2-keto-3-deoxy-6-phosphogluconate aldolase, was about 20 times higher than in the parent. This strain produced 1.2 times more L-lysine than the parent producer. Perhaps, then, the supply of pyruvate was a bottleneck in L-lysine production in the L-lysine producer of M. methylotrophus.
    Download PDF (118K)
  • Shin-ichiro YOKOYAMA, Tohru SUZUKI
    2008 Volume 72 Issue 10 Pages 2660-2666
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    An equol-producing bacterium was newly isolated from the feces of healthy humans and its morphological and biochemical properties were characterized. The cells were obligate anaerobes. They were non-sporulating, non-motile, gram-positive bacilliform bacteria with a pleomorphic morphology. The strain was catalase-positive, and oxidase-, urease-, and indole-negative. The only other sugar utilized by the strain was glycerin. The strain also degraded gelatin, but not esculin. It was most closely related to Eggerthella hongkongensis HKU10, with 93.3% 16S rDNA nucleotide sequence homology. Based on these features, the isolate was identified as a novel species of the genus Eggerthella. It was named Eggerthella sp. YY7918. Strain YY7918 converted substrates daidzein and dihydrodaidzein into S-equol, but did not convert daidzin, glysitein, genistein, or formononetin into it. An antimicrobial susceptibility assay indicated that strain YY7918 was susceptible to aminoglycoside-, tetracycline-, and new quinolone-antibiotics.
    Download PDF (161K)
  • Hiroyuki SONODA, Atsushi SUGIMURA
    2008 Volume 72 Issue 10 Pages 2675-2680
    Published: October 23, 2008
    Released: October 23, 2008
    [Advance publication] Released: October 07, 2008
    JOURNALS FREE ACCESS
    Recombinant human growth hormone (r-hGH) overexpressed in Escherichia coli forms inactive and insoluble aggregates as inclusion bodies in the cytoplasm. The efficient solubilization of inclusion bodies is critical for cost-effective production. Contrary to a previous report, in our production system, the solubilization method by alkaline treatment including 2 M urea was ineffective. Hence various buffers containing different concentrations of urea or guanidine hydrochloride (GnHCl) at neutral and alkaline pH were attempted. Efficient solubilization (about 90%) was observed in 100 mM Tris buffer, pH 8.0, with more than 4 M GnHCl, and at pH 12.5 with more than 2 M GnHCl, but not with about 8 M of urea. The r-hGH solubilized at pH 12.5 containing 2 M GnHCl was refolded by simple dilution and purified by DEAE Sepharose anion-exchange chromatography. The biological activity of the resulting r-hGH was comparable with commercially available r-hGH in in vitro cell proliferation assay using the hGH-dependent cell line.
    Download PDF (122K)
Microbiology & Fermentation Technology Note
Errata
feedback
Top