Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 73 , Issue 10
Showing 1-41 articles out of 41 articles from the selected issue
Award Review
  • Hiroyasu ONAKA
    2009 Volume 73 Issue 10 Pages 2149-2155
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    The biosynthesis of staurosporine, rebeccamycin, and goadsporin, which are produced by actinomycetes and contain characteristic heterocyclic rings, was characterized by genetic methods. Staurosporine and rebeccamycin contain an indolocarbazole ring synthesized from two molecules of tryptophan, with indolepyruvic acid imine and chromopyrrolic acid as biosynthetic intermediates. A tetrameric hemoprotein synthesizes chromopyrrolic acid, and cytochrome P450 peroxidase catalyzes the intramolecular C–C coupling and decarboxylation of chromopyrrolic acid to form the indolocarbazole core. Goadsporin is a thiopeptide containing thiazole and oxazole heterocyclic rings. The structural gene godA is ribosomally translated to a goadsporin precursor peptide, and oxazole, methyloxazole, and thiazole rings are derived from serine, threonine, and cystein through post-translational modifications. On the basis of these knowledges, a wide variety of indolocarbazole and goadsporin analogs through the rational gene recombination and disruption of these biosynthetic genes were successfully produced.
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Organic Chemistry Regular Papers
  • Phebe HENDRA, Yukiharu FUKUSHI, Yasuyuki HASHIDOKO
    2009 Volume 73 Issue 10 Pages 2172-2182
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    The first total syntheses of benzophenone glucopyranosides reported from Phaleria macrocarpa and related benzophenone glucopyranosides were successfully carried out. The alkoxy groups present ortho to the carbonyl group in polyalkoxybenzophenones were selectively deprotected by AlCl3–PhNMe2 in high yields, leaving other alkoxy groups unaffected. It was concluded in the current synthetic study that all the reported benzophenone glucopyranosides possessed the same structure as 2,4′,6-trihydroxy-4-methoxybenzophenone 2-O-β-D-glucopyranoside.
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  • Ryutaro KIYOTA, Rei YAMAKAWA, Kikuo IWABUCHI, Keita HOSHINO, Tetsu AND ...
    2009 Volume 73 Issue 10 Pages 2252-2256
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    Adult males of the grape borer, Xylotrechus pyrrhoderus, secrete (S)-2-hydroxy-3-octanone [(S)-1] and (2S,3S)-2,3-octanediol [(2S,3S)-2] from their nota of prothoraces as sex pheromone components. Their structural similarity suggests that one of them is the biosynthetic precursor of the other component. In order to confirm the biochemical conversion, deuterated derivatives of both components were synthesized by starting from a Wittig reaction between hexanal and an ylide derived from D5-iodoethane and ending with enantiomeric resolution by chiral HPLC. The molecular ions of 1 and 2 could scarcely be detected by using a GC-MS analysis, and the labeled compounds showed similar mass spectra to the unlabeled pheromone components. However, several fragment ions, including four deuterium atoms, were observed in the mass spectra of their acetate derivatives, indicating that the conversion could be confirmed by examining a compound with the diagnostic ions after acetylation of the volatiles collected from insects treated with the labeled precursors.
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  • Tatsuo YAJIMA, Makiko KIMURA, Mami NAKAKOJI, Takao HORIKAWA, Yurie TOK ...
    2009 Volume 73 Issue 10 Pages 2293-2298
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    An X-ray crystal structural analysis revealed that (2S,3S)-N-acetyl-2-amino-3-methylpentanoic acid (N-acetyl-L-isoleucine; Ac-L-Ile) and (2R,3S)-N-acetyl-2-amino-3-methylpentanoic acid (N-acetyl-D-alloisoleucine; Ac-D-aIle) formed a molecular compound containing one Ac-L-Ile molecule and one Ac-D-aIle molecule as an unsymmetrical unit. This molecular compound is packed with strong hydrogen bonds forming homogeneous chains consisting of Ac-L-Ile molecules or Ac-D-aIle molecules and weak hydrogen bonds connecting these homogeneous chains in a fashion similar to that observed for Ac-L-Ile and Ac-D-aIle. Recrystallization of an approximately 1:1 mixture of Ac-L-Ile and Ac-D-aIle from water gave an equimolar molecular compound due to its lower solubility than that of Ac-D-aIle or especially Ac-L-Ile. The results suggest that the equimolar mixture of Ac-L-Ile and Ac-D-aIle could be obtained from an Ac-L-Ile-excess mixture by recystallization from water.
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  • Takashi HASHIMOTO, Takuya TASHIRO, Takeshi KITAHARA, Kenji MORI, Mitsu ...
    2009 Volume 73 Issue 10 Pages 2299-2302
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    Basidifferquinones, isolated from Streptomyces sp., are potent inducers of fruiting-body formation in the basidiomycete, Polyporus arcularius. The first synthesis of (±)-basidifferquinone C was accomplished by starting from 3,5-dihydroxy-2-naphthoic acid.
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Organic Chemistry Notes
Biochemistry & Molecular Biology Regular Papers
  • Takehito SUZUKI, Chiemi MORI, Hiroshi YOSHIKAWA, Yoko MIYAZAKI, Norio ...
    2009 Volume 73 Issue 10 Pages 2163-2166
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    We clarified nitric oxide (NO) production in the rat uterus by electron paramagnetic resonance spectroscopy and with Fe-N-(dithiocarboxy) sarcosine complex (an NO-trapping reagent). We examined changes in NO production in the whole uterus, decidua, and myometrium (gestational days 13.5–21.5). The expression of nitric oxide synthase (NOS) isoforms was also examined by quantitative reverse transcription-polymerase chain reaction. The uterine NO levels were low on day 13.5, peaked on day 17.5, and thereafter decreased significantly. The NO production levels in the decidua and myometrium were the same on day 13.5, but the levels in the decidua were 2- to 4-fold higher than those in the myometrium from day 15.5 onwards. The NOS-2 mRNA expression pattern correlated well with changes in the NO levels in the decidua, whereas the NOS-3 mRNA was expressed constantly during gestation. Thus NOS-2-generated NO in the decidua contributed significantly to uterine NO levels.
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  • Hyeonseok KO, Young-Joo KIM, Jin-Soo PARK, Jeong Hill PARK, Hyun Ok YA ...
    2009 Volume 73 Issue 10 Pages 2183-2189
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
    JOURNALS FREE ACCESS
    Supplementary material
    Our previous study indicated that ginsenoside Rk1 has anti-tumor activity and that its mode of action in HepG2 cells treated for 48 h involves coordinated inhibition of telomerase and induction of apoptosis. In the present study, we found that Rk1 induces both G1 phase arrest and autophagy, but not apoptosis, at an earlier stage of treatment. A 24-h incubation of HepG2cells with Rk1 induced G1 phase arrest. Rk1-induced autophagy was documented by the conversion of microtubule associated protein light chain 3 (LC3)-I to LC3-II, an autophagosome marker, and monodansylcadaverine (MDC) incorporation into autolysosomes. Combination of Rk1 with an autophagy inhibitor, such as bafilomycin A1 or beclin 1 siRNA, enhanced the anti-tumor effect of Rk1. These results imply that autophagy functions as a survival mechanism in HepG2 cells against Rk1-induced apoptosis. Taken together, our results support the use of autophagy inhibitors in combination with Rk1 as an effective anti-cancer regimen in HepG2 cells.
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  • Shi-Wu DONG, Da-Jun YING, Xiao-Jun DUAN, Zhao XIE, Zi-Jiang YU, Chu-Ho ...
    2009 Volume 73 Issue 10 Pages 2226-2233
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    To treat bone defects, tissue-engineering methods combine an appropriate scaffold with cells and osteogenic signals to stimulate bone repair. Mesenchymal stem cells (MSCs) derived from adult bone marrow are an ideal source of cells for tissue engineering, in particular for applications in skeletal and hard tissue repair. Core binding factor α1 (Cbfa1) is an essential transcription factor for osteoblast differentiation. However, the effects of Cbfa1 on MSCs in vitro and in vivo have not been well characterized. In this study, we found that MSCs modified genetically to express Cbfa1 promoted the healing of segmental defects of the radius in rabbits. First, osteogenic differentiation of MSCs transfected with an adenovirus encoding Cbfa1 was demonstrated. Expression of mRNA from a number of osteoblastic marker genes, including osteocalcin, osteopontin, and type I collagen, was detected. In addition, alkaline phosphatase activity and increased osteocalcin content were observed. The cells expressing the Cbfa1 gene were then combined with acellular bone extracellular matrix in a flow perfusion culture system. Finally, the cell–matrix constructs were implanted into radius defects in the rabbit model. After 12 weeks, radiographic, histological, and biomechanical analyses showed that MSCs modified with the Cbfa1 gene resulted in a significantly higher amount of newly-formed bone and rebuilding of the marrow cavity than control cell–matrix constructs. This study indicates that MSCs modified with the Cbfa1 gene can act as suitable seed cells for the regeneration of bone defects.
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  • Kaori MIYABE, Atsushi ISHIKAWA
    2009 Volume 73 Issue 10 Pages 2257-2260
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    Activation of the hypersensitive response (HR) triggers localized acquired resistance (LAR) and systemic acquired resistance (SAR). Recently we found that Arabidopsis thaliana lesion initiation 3 (len3) plants develop lesions on leaves without pathogen attack, constitutively express PR genes, and accumulate elevated levels of SA. Hence we hypothesized that a signal important for LAR and SAR accumulates in the intercellular fluids (IFs) of the len3 plants. Infiltration of the IF from len3 plants induced PR-2 expression in local leaves but not in the systemic leaves of the wild type plants, suggesting that the elicitor activity of the IF contributes to LAR but not to SAR. Induction of PR-2 was dependent on SA signaling and ET signaling, and the elicitor in the IF was associated with molecules in the range of >100 kDa. These results suggest that len3 plants accumulate the elicitor in the IF, and that this might play a role in the establishment of LAR.
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  • Kohei BUTSUSHITA, Shin-Ichi FUKUOKA, Koh IDA, Yasuhiro ARII
    2009 Volume 73 Issue 10 Pages 2274-2280
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    Annexin A4 (Anx4) possesses four repeat domains with one Ca2+-binding site (CBS) in each domain. In this study, we resolved two crystal structures of the Na+-bound form at high resolution (1.58 and 1.35 Å). This is the first report that Anx4 binds the Na+ ion in CBSs. Electron density maps, valence screening, and atomic absorbance spectrometry confirmed that Anx4 bound the Na+ ion. One structure (1.58 Å) bound the Na+ ion in CBS I, whereas another structure (1.35 Å) bound the Na+ ion in CBS II and CBS III. We compared the two Na+-bound forms by superimposing their Cα traces. The Cα atoms of CBS III largely moved by coordination of the Na+ ion. In the Cα atoms of CBS I, however, little change resulted from Na+-coordination. Only the side chain of Glu71 was moved by Na+-coordination in CBS I. These results indicate that Anx4 also binds not only Ca2+ but also Na+ ion in the CBS.
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  • Tomoya MAEDA, Taro SAKAI, Masaaki WACHI
    2009 Volume 73 Issue 10 Pages 2281-2286
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    The Corynebacterium glutamicum NCgl2281 gene encodes an RNase E/G family endoribonuclease having an additional N-terminal domain of unknown function. In this study, we constructed plasmids expressing the full length (FL) and the N-terminally truncated form (ΔN) of NCgl2281 and examined their complementation ability as to Escherichia coli rng::cat and rne-1 mutations. Both FL- and ΔN-NCgl2281 rescued the defects caused by the rng::cat mutation, i.e., accumulation of 16S rRNA precursor, overproduction of the AdhE protein, and growth inhibition on M9 glucose medium. On the other hand, they did not complement the rne-1 mutation. These results indicate that the C. glutamicum NCgl2281 endoribonuclease is functionally more closely related to the E. coli RNase G than to RNase E.
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  • Toshihisa KOTAKE, Kiminari KITAZAWA, Ryohei TAKATA, Kohei OKABE, Hitom ...
    2009 Volume 73 Issue 10 Pages 2303-2309
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    Supplementary material
    A gene encoding exo-β-(1→3)-galactanase from Irpex lacteus was cloned by reverse transcriptase-PCR. The deduced amino acid sequence showed high similarity with exo-β-(1→3)-galactanases from other sources. The molecular mass of the mature form was calculated to be 45,520 Da. The gene product expressed in Pichia pastoris specifically hydrolyzed β-(1→3)-galactooligosaccharides, as did other exo-β-(1→3)-galactanases. The recombinant enzyme showed high activity toward arabinogalactan-proteins (AGPs) from radish as well as β-(1→3)-galactan. Product analysis revealed that the enzyme released β-(1→6)-galactobiose, β-(1→6)-galactotriose, and α-L-arabinofuranosyl-(1→3)-β-galactosyl-(1→6)-galactose together with Gal from β-(1→3)-galactans attached with and without β-(1→6)-galactosyl branches prepared from acacia gum. These results indicate that the exo-β-(1→3)-galactanase from I. lacteus efficiently hydrolyzes β-(1→3)-galactan main chains of AGPs by bypassing β-(1→6)-galactosyl side chains.
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  • Masaki YASUDA, Asako IGUCHI-YOKOYAMA, Shin-ichi MATSUYAMA, Hajime TOKU ...
    2009 Volume 73 Issue 10 Pages 2310-2316
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    Supplementary material
    The LolCDE complex is an ATP-binding cassette transporter that mediates the release of newly synthesized lipoproteins from the cytoplasmic membrane of gram-negative bacteria, which results in the initiation of outer-membrane sorting of lipoproteins through the Lol pathway. LolCDE is composed of one copy each of membrane subunits LolC and LolE, and two copies of nucleotide-binding subunit LolD. In this study, we examined the membrane topology of LolC and LolE by PhoA fusion analysis. Both LolC and LolE were found to have four transmembrane segments with a large periplasmic loop exposed to the periplasm. Despite similarities in sequence and topology, the accessibility of a sulfhydryl reagent to Cys introduced into the periplasmic loop suggested that the structure of the periplasmic region differs between LolC and LolE. Inhibition of the release of lipoproteins by the sulfhydryl reagent supported a previous proposal that LolC and LolE have distinct functions.
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Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Communications
  • BANDARA P.K.G.S.S., Kosaku TAKAHASHI, Michio SATO, Hideyuki MATSUURA, ...
    2009 Volume 73 Issue 10 Pages 2356-2359
    Published: October 23, 2009
    Released: October 23, 2009
    JOURNALS FREE ACCESS
    Jasmonic acid (JA) is a plant hormone that plays important roles in a large number of processes in stress adaptation and development in flowering plants. A search of genome database indicated the existence of allene oxide synthase (AOS), an enzyme of JA biosynthesis, in Physcomitrella patens, a model plant among mosses. In this study, the presence of JA was detected in P. patens. The recombinant AOS of P. patens, which was overexpressed in Escherichia coli, showed AOS activity. These data suggest that the octadecanoid pathway also exists in P. patens.
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  • Zui FUJIMOTO, Satoshi KANEKO, Wook-Dong KIM, Gwi-Gun PARK, Mitsuru MOM ...
    2009 Volume 73 Issue 10 Pages 2360-2364
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    The crystal structure of Umbelopsis vinacea α-galactosidase I, which belongs to glycoside hydrolase family 27, was determined at 2.0 Å resolution. The monomer structure was well conserved with those of glycoside hydrolase family 27 enzymes. The biological tetramer structure of this enzyme was constructed by the crystallographic 4-fold symmetry, and tetramerization appeared to be caused by three inserted peptides that were involved in the tetramer interface. The quaternary structure indicated that the substrate specificity of this enzyme might be related to the tetramer formation. Three N-glycosylated sugar chains were observed, and their structures were found to be of the high-mannose type.
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Food & Nutrition Science Regular Papers
  • Mi-Ran CHA, Mi-young YOON, Eun-Soon SON, Hae-Ryong PARK
    2009 Volume 73 Issue 10 Pages 2167-2171
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    Pancreatic cancer cells are sometimes exposed to stressful microenvironments such as glucose deprivation, hypoxia, and starvation of other nutrients. These stresses, which are characteristic of poorly vascularized solid tumors, activate the unfolded protein response (UPR). The UPR is a stress-signaling pathway present in tumor cells that is associated with molecular chaperone GRP78. Induction of GRP78 has been found to increase cell survival and decrease apoptotic potential through genetic alterations. Thus GRP78 may represent a novel target in the development of anticancer drugs. Here we established a novel screening program to identify chaperone modulators that exhibit preferential cytotoxic activity in glucose-deprived pancreatic cancer cells. During the course of our screening, we isolated an active substance, Ponciri Fructus (PF), from an herbal medicine source and identified it as a down-regulator of GRP78. As expected, PF inhibited expression of the GRP78 protein under glucose-deprivation conditions in a dose-dependent manner. Furthermore, it induced selective cytotoxicity against glucose-deprived cancer cells; this effect was not observed under normal growth conditions. We also detected apoptotic bodies on Hoechst staining and attempted to determine whether PF-induced apoptosis involved caspase-3 activation. Our results suggest that the GRP78-inhibitory action of PF was dependent on strict hypoglycemic conditions and that it resulted in the selective death of glucose-deprived pancreatic cancer cells.
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  • Cheol-Ho PARK, Phil-Sun OH, Kye-Taek LIM
    2009 Volume 73 Issue 10 Pages 2196-2202
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    The present study was performed to investigate the anti-inflammatory potential of 115 kDa glycoprotein isolated from Zanthoxylum piperitum DC leaves (ZPDC glycoprotein) in primary cultured mouse thymocytes. To determine whether the ZPDC glycoprotein has inhibitory capacity against inflammation in vitro, we evaluated the activities of inflammation-related factors such as phosphorylations of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK) 1/2, and the activities of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) in 12-O-tetradecanoylphorbol 13-acetata (PMA, 50 nM)-treated mouse thymocytes. Our results showed that the ZPDC glycoprotein (200 μg/ml) has a suppressive effect on the expression of MAPK (ERK1/2 and p38 MAPK), on mRNA expression of pro-inflammatory cytokines (TNF-α and IL-1β), and on protein expression of pro-inflammatory proteins (iNOS and COX-2). We speculate that the ZPDC glycoprotein is an example of a natural compound that blocks pro-inflammatory signal transduction pathways.
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  • Lila OTANI, Toshio NINOMIYA, Megumi MURAKAMI, Katsuhiro OSAJIMA, Hisan ...
    2009 Volume 73 Issue 10 Pages 2203-2209
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    An enzymatic hydrolysate of sardine protein (sardine peptide, SP) derived from sardine muscle possesses angiotensin I-converting enzyme (ACE) inhibitory activity. In the present study, we investigated the effect of SP on the blood glucose levels in stroke-prone spontaneously hypertensive rats (SHRSPs). Ten-week-old SHRSPs were assigned to three groups. The control group was given tap water for 4 weeks, while the experimental groups were given water containing SP (1 g/kg/d) or an ACE inhibitor, captopril (8 mg/kg/d). Treatment with SP and captopril decreased ACE activity in the kidney, aorta, and mesentery. There were no differences in fasting blood glucose levels among the three groups, whereas SP and captopril administration significantly suppressed the increase in blood glucose after glucose loading in the control SHRSPs. No difference was observed in plasma insulin levels among the three groups. Thus treatment with captopril and ACE-inhibitory sardine peptides ameliorated the glucose tolerance of this rat strain.
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  • Hideko MOTOJIMA, Parida YAMADA, Junkyu HAN, Masuo OZAKI, Hideyuki SHIG ...
    2009 Volume 73 Issue 10 Pages 2210-2216
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    The physicochemical and biological properties of fulvic acid extracted and purified from excess sludge and solubilized excess sludge were studied. Solubilization was introduced to improve the recovery rate of fulvic acid from the sludge. The structural features of fulvic acid from excess sludge and solubilized excess sludge were characterized by using an elemental analysis, Fourier transform infrared spectroscopy and 1H-nuclear magnetic resonance spectroscopy, and were compared with fulvic acid extracted from peat which had an inhibitory effect on the type I allergy in our previous study. The results show that they had a higher aliphatic characteristic with lower oxygen group content than fulvic acid from peat, and that the aliphatic characteristic was further strengthened by the use of solubilization. The biological properties of fulvic acid from excess sludge and solubilized excess sludge showed an inhibitory effect on β-hexosaminidase release at the antigen-antibody binding stage and antigen-receptor binding stage by using rat basophilic leukemia cells.
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  • Masao YAMASAKI, Yusuke OMI, Naoko FUJII, Asako OZAKI, Akihiko NAKAMA, ...
    2009 Volume 73 Issue 10 Pages 2217-2221
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    Cruciferous vegetables and their isothiocyanates are promising foods and agents for cancer prevention. We focus here on the effects of mustard oil (SMO) in a variety of the Japanese radish, Shibori Daikon (Raphanus sativus), on the proliferation of 3Y1 rat fibroblasts and the H-ras-transformed derivative, HR-3Y1-2. SMO (1.6 μg/ml) inhibited the proliferation of HR-3Y1-2, but not 3Y1 after 24 h after treatment. A cell cycle analysis showed that SMO induced G2/M arrest after 6 h, although this effect was not observed 24 h after the treatment. SMO transiently decreased the cellular reduced glutathione level accompanied with up-regulation of the intracellular reactive oxygen species 2–3 h post-treatment. Glutathione ethyl ester and N-acetyl-L-cysteine prevented the growth inhibitory effect of SMO. This mustard oil extract consisted of 95.6% 4-methylthio-3-butenyl isothiocyanate and 4.4% 4-methylthiobutyl isothiocyanate. SMO selectively inhibited H-ras-transformed 3Y1 cells associated with transient oxidative stress via reduced glutathione (GSH) depletion.
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  • Yuichiro TAKANAMI, Takako MORIYAMA, Yasutaka KOSAKA, Tsutomu NAKAYAMA
    2009 Volume 73 Issue 10 Pages 2222-2225
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    An analysis of hydrogen peroxide in an aqueous extract of cigarette smoke, which contains many redox-active compounds, requires a method with high selectivity. An aqueous extract of the particulate phase of cigarette smoke was analyzed by HPLC with an electrochemical detector (ECD). Samples were prepared by collecting the particulate phase of the cigarette smoke on a glass fiber filter and extracting it with a phosphate buffer. The obtained solution was purified by using a Waters Oasis MCX cation-exchange cartridge, and then analyzed by an HPLC-ECD system with a Shodex KS-801 mixed-mode resin column. Pre-injecting hydrogen peroxide at a high concentration into the HPLC instrument stabilized the analytical results. The recovery of hydrogen peroxide by using an extract of the particulate phase of the cigarette smoke was more than 80%. An increase in the amount of hydrogen peroxide was observed during extraction with the phosphate buffer at higher pH values. In contrast, extraction with phosphoric acid did not increase the amount of hydrogen peroxide during extraction.
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  • Toshiro MATSUI, Sachiko KOREMATSU, Eui-Baek BYUN, Taichi NISHIZUKA, Sh ...
    2009 Volume 73 Issue 10 Pages 2246-2251
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    Apple (Malus pumila) procyanidins led to a potent vasorelaxation effect in 1.0 μM phenylephrine-contractive rat thoracic aorta. Relaxation was greatly reduced by 70 mM KCl as well as by removal of the endothelium, suggesting that it was associated with endothelium-dependent hyperpolarization. Neither cAMP synthesis inhibition nor NAD(P)H oxidase inhibition abolished the effect. In contrast, complete abolition by a soluble guanylyl cyclase inhibitor revealed that apple procyanidins were mainly involved in the cGMP production pathways. In the presence of NG-monoethyl-L-arginine or tetraethylammonium chloride, the effect was still observed at higher concentrations (>25 μg/ml), while their combination completely diminished the effect. Vasorelaxation was to some extent affected by paxillin, apamin and glybenclamide, and was greatly affected by 4-aminopyridine and by BaCl2. These results indicate that procyanidin-induced vasorelaxation is associated with NO-cGMP pathway in combination with hyperpolarization due to multiple activation of Ca2+-dependent and -independent K+ channels.
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  • Yoshinobu SHIRAHASHI, Hirohito WATANABE, Fumitaka HAYASE
    2009 Volume 73 Issue 10 Pages 2287-2292
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    Blue, red, and yellow pigments were formed in the D-xylose (1 M)-glycine (0.1 M) reaction system. Novel red pigments were isolated and purified from the reaction solution, designated Red-M1 (red Maillard intermediate-1) and Red-M2 (red Maillard intermediate-2). Red-M1 was identified as 1,4,6,9-tetracarboxymethyl-5-(1,2,3,4-tetrahydroxybutyl)-8-hydroxymethyl-3-(2,3-dihydroxypropyl)-5,6-dihydro-pyrrolo[2′,3′:4,5]pyrrolo[2,3-e]pyrrolo[3,2-b]azepine-9-ium. NMR and CD data indicated that Red-M2 was a diastereomer of Red-M1. They are assumed to be important Maillard reaction intermediates through the formation of melanoidins as well as blue pigments.
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Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Pattaraporn YUKPHAN, Taweesak MALIMAS, Yuki MURAMATSU, Mai TAKAHASHI, ...
    2009 Volume 73 Issue 10 Pages 2156-2162
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
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    Two isolates, AC04T and AC05, were isolated from the flowers of red ginger collected in Chiang Mai, Thailand. In phylogenetic trees based on 16S rRNA gene sequences, the two isolates were included within a lineage comprised of the genera Acidomonas, Gluconacetobacter, Asaia, Kozakia, Swaminathania, Neoasaia, Granulibacter, and Tanticharoenia, and they formed an independent cluster along with the type strain of Tanticharoenia sakaeratensis. The calculated pair-wise sequence similarities of isolate AC04T were 97.8–92.5% to the type strains of the type species of the 11 genera of acetic acid bacteria. The DNA base composition was 66.0–66.1 mol % G+C with a range of 0.1 mol %. A single-stranded, labeled DNA from isolate AC04T presented levels of DNA-DNA hybridization of 100, 85, 4, and 3% respectively to DNAs from isolates AC04T and AC05 and the type strains of Tanticharoenia sakaeratensis and Gluconacetobacter liquefaciens. The two isolates were unique morphologically in polar flagellation and physiologically in intense acetate oxidation to carbon dioxide and water and weak lactate oxidation. The intensity in acetate oxidation almost equaled that of the type strain of Acetobacter aceti. The two isolates had Q-10. Isolate AC04T was discriminated from the type strains of the type species of the 11 genera by 16S rRNA gene restriction analysis using restriction endonucleases TaqI and Hin6I. The unique phylogenetic, genetic, morphological, physiological, and biochemical characteristics obtained indicate that the two isolates can be classified into a separate genus, and Ameyamaea chiangmaiensis gen. nov., sp. nov. is proposed. The type strain is isolate AC04T (=BCC 15744T, =NBRC 103196T), which has a DNA G+C content of 66.0 mol %.
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  • Susumu MASUDA, Kaori KIKUCHI, Yuko MATSUMOTO, Toshikazu SUGIMOTO, Hiro ...
    2009 Volume 73 Issue 10 Pages 2190-2195
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
    JOURNALS FREE ACCESS
    We have reported on high enzyme production by submerged culture of Aspergillus kawachii using barley with the husk (whole barley). To elucidate the mechanism underlying this high enzyme production, we performed a detailed analysis. Aspergillus oryzae RIB40 was submerged-cultured using whole barley and milled whole barley. Enzyme production was analyzed in terms of changes in medium components and gene expression levels. When whole barley was used, high production of glucoamylase and α-amylase and high gene expression levels of these enzymes were observed. Low ammonium concentrations were maintained with nitrate ion uptake continuing into the late stage using whole barley. These findings suggest that the sustainability of nitrogen metabolism is related to high enzyme production, and that a mechanism other than that associated with the conventional amylase expression system is involved in this relationship.
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  • Ye-Wang ZHANG, Ponnandy PRABHU, Jung-Kul LEE
    2009 Volume 73 Issue 10 Pages 2234-2239
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
    JOURNALS FREE ACCESS
    Bacillus licheniformis L-arabinose isomerase (BLAI) with a broad pH range, high substrate specificity, and high catalytic efficiency for L-arabinose was immobilized on various supports. Eupergit C, activated-carboxymethylcellulose, CNBr-activated agarose, chitosan, and alginate were tested as supports, and Eupergit C was selected as the most effective. After determination of the optimum enzyme concentration, the effects of pH and temperature were investigated using a response surface methodology. The immobilized BLAI enzyme retained 86.4% of the activity of the free enzyme. The optimal pH for the immobilized BLAI was 8.0, and immobilization improved the optimal temperature from 50 °C (free enzyme) to a range between 55 and 65 °C. The half life improved from 2 at 50 °C to 212 h at 55 °C following immobilization. The immobilized BLAI was used for semi-continuous production of L-ribulose. After 8 batch cycles, 95.1% of the BLAI activity was retained. This simple immobilization procedure and the high stability of the final immobilized BLAI on Eupergit C provide a promising solution for large-scale production of L-ribulose from an inexpensive L-arabinose precursor.
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  • Ryoji MIZUNO, Hitomi ICHINOSE, Tomoko MAEHARA, Koji TAKABATAKE, Satosh ...
    2009 Volume 73 Issue 10 Pages 2240-2245
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
    JOURNALS FREE ACCESS
    Basidiomycetes have the ability to degrade lignocellulosic biomass, and some basidiomycetes produce alcohol dehydrogenase. These characteristics may be useful in the direct production of ethanol from lignocellulose. Ethanol fermentation by basidiomycetes was investigated to examine the possibility of ethanol production by consolidated bioprocessing (CBP) using Flammulina velutipes. F. velutipes converted D-glucose to ethanol with a high efficiency (a theoretical ethanol recovery rate of 88%), but ethanol production from pentose was not observed. These properties of F. velutipes are similar to those of Saccharomyces cerevisiae, but the basidiomycete converted not only sucrose, but also maltose, cellobiose, cellotriose, and cellotetraose to ethanol, with almost the same efficiency as that for D-glucose. From these results, we concluded that F. velutipes possesses advantageous characteristics for use in CBP.
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  • Mitsuaki TABUCHI, Yasuhiro KAWAI, Makiko NISHIE-FUJITA, Rinji AKADA, T ...
    2009 Volume 73 Issue 10 Pages 2261-2267
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
    JOURNALS FREE ACCESS
    Our understanding of the molecular mechanisms of bacterial pathogenesis has been improved especially by the discovery of host cell contact-dependent secretion systems such as the type-III secretion system (T3SS) found in numerous pathogens. Although the identification of pathogen effectors translocated into host cells through T3SS is essential to the understanding of pathogenesis, their general sequence uniqueness confound attempts to identify such proteins by sequence homology. Here we report the development of a functional high-throughput screening system for pathogen effectors in yeast that consists of a GatewayTM-compatible Tet-Off inducible expression vector and a yeast strain expressing a reporter, facilitating identification of the effectors affecting host vesicular trafficking pathways. We evaluated this system and optimized the screening condition using several known pathogen effectors. We found this system useful in functional characterization of pathogen effector and it can be adapted to functional high-throughput screening as well.
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  • Hiroyuki HIRAISHI, Masahiro OKADA, Iwao OHTSU, Hiroshi TAKAGI
    2009 Volume 73 Issue 10 Pages 2268-2273
    Published: October 23, 2009
    Released: October 23, 2009
    [Advance publication] Released: October 07, 2009
    JOURNALS FREE ACCESS
    Rsp5 is an essential ubiquitin ligase in Saccharomyces cerevisiae. We have found that the Ala401Glu rsp5 mutant is hypersensitive to various stresses, suggesting that Rsp5 is a key enzyme for yeast cell growth under stress conditions. The ubiquitination and the subsequent degradation of stress-induced misfolded proteins are indispensable for cell survival under stress conditions. In this study, we analyzed the ubiquitin-conjugating enzyme Ubc4 and the poly-ubiquitination of targeted proteins involved in the function of Rsp5 under ethanol stress conditions. Ubc4 was found to be important in yeast cell growth and poly-ubiquitination of the bulk proteins in the presence of ethanol. The general amino acid permease Gap1 is poly-ubiquitinated via Lys63 and is down-regulated after the addition of ammonium ions through a process requiring Rsp5. We found that Gap1 was removed from the plasma membrane in the presence of ethanol in a Rsp5-dependent manner, and that the disappearance of Gap1 required Ubc4 and involved the lysine residues of ubiquitin. Our results also indicate that Lys6 of ubiquitin might inhibit the disappearance of Gap1. These results suggest that Rsp5 down-regulates the ethanol-induced misfolded forms of Gap1. In addition, it appears that the substrates of Rsp5 are appropriately poly-ubiquitinated via different lysine residues of ubiquitin under various growth conditions.
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Microbiology & Fermentation Technology Note
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