Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 74 , Issue 3
Showing 1-45 articles out of 45 articles from the selected issue
Award Reviews
  • Hideaki NANAMIYA, Fujio KAWAMURA
    2010 Volume 74 Issue 3 Pages 451-461
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Sporulation is one of the adaptive responses used by Bacillus subtilis, a well-characterized gram-positive soil bacterium, when cells encounter adverse growth conditions, such as nutrient limitation. The activity and/or intracellular levels of ribosomes must be tightly controlled during sporulation, because protein translation and ribosome synthesis consume vast amounts of energy, but very little is known about the mechanisms that regulate these processes during sporulation in B. subtilis. Therefore, to understand the role of the ribosome in sporulation, as well as the function of the B. subtilis ribosome in translation, we developed genetic and biochemical systems to analyze the constituents of the ribosome. In developing a proteomic map of ribosomal proteins, we found that two types of L31 protein (RpmE and YtiA) were associated alternatively with the ribosome. Expression of ytiA is induced under zinc-limiting conditions due to de-repression of transcription by Zur, a transcriptional repressor that represses the transcription of genes encoding the zinc-uptake machinery. Under zinc-limiting conditions, RpmE, which contains one zinc atom per molecule, is replaced by YtiA, which does not contain zinc, in the 50S subunit of the ribosome. Given that RpmE released from the ribosome is unstable in cells, this replacement might contribute to the mobilization of zinc by supplying the zinc from the released RpmE into the cells under zinc-limiting conditions. In addition, genes that encode two types of S14 (RpsN and YhzA) were also found in the genome of B. subtilis. RpsN contains zinc-binding motifs whereas YhzA does not. As in the case of ytiA, the transcription of yhzA is negatively regulated by Zur. However, unlike the L31 proteins, switching between the two types of S14 protein was not observed even under zinc-limiting conditions. Further studies strongly suggested that YhzA forms a “fail-safe” mechanism to maintain the function of the 30S subunit of the ribosome under zinc-limiting conditions. These results can provide novel insight into the role of ribosomal protein paralogs in the ribosome under zinc-limiting conditions.
    Download PDF (444K)
  • Koji NAGATA
    2010 Volume 74 Issue 3 Pages 462-470
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Peptides and proteins with similar amino acid sequences can have different biological functions. Knowledge of their three-dimensional molecular structures is critically important in identifying their functional determinants. In this review, I describe the results of our and other groups’ structure-based functional characterization of insect insulin-like peptides, a crustacean hyperglycemic hormone-family peptide, a mammalian epidermal growth factor-family protein, and an intracellular signaling domain that recognizes proline-rich sequence.
    Download PDF (560K)
  • Takehito INABA
    2010 Volume 74 Issue 3 Pages 471-476
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Plastids are a diverse group of organelles found in plants and some parasites. Chloroplasts are the archetypical plastids and are present in photosynthetic plant cells. Because most plastid proteins are encoded by the nuclear genome, plastid biogenesis relies on importing these proteins into the plastid. On the other hand, changes in functional or metabolic states of plastids have been known to affect the expression of nuclear genes encoding plastid proteins, and are collectively called “plastid signals.” This regulation is also important for maintaining plastid function. This review focuses on the roles of these anterograde and retrograde pathways in plastid biogenesis and environmental adaptation.
    Download PDF (210K)
Analytical Chemistry Regular Paper
  • Yasuhiro KAKIGI, Naoki MOCHIZUKI, Takeshi ICHO, Takashi HAKAMATSUKA, Y ...
    2010 Volume 74 Issue 3 Pages 590-594
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    A new HPLC method using charged aerosol detection was developed for the determination of terpene lactones in a Ginkgo leaf extract. The linearity of the standard curves was excellent (r>0.999). The repeatability of the method was less than 3%, and its reproducibility was less than 5% for each analyte. The limit of detection was between 0.087 and 0.45 μg/ml. The developed method was applied to the analysis of terpene lactones in Ginkgo leaf products distributed in the Japanese market. The results suggest that some health food products contained approximately equivalent amounts of terpene lactones to those in the medical product and that the proportion of terpene lactones varied in each health product.
    Download PDF (183K)
Organic Chemistry Regular Papers
  • Takahiro NODA, Masateru ONO, Kazuhiko IIMURE, Tomohiro ARAKI
    2010 Volume 74 Issue 3 Pages 563-568
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    The conidium of the entomopathogenic fungus Nomuraea rileyi has been found to germinate rapidly in the presence of host insect-derived extracts. Thus the extract appears to contain an important factor involved in host recognition by N. rileyi. However, the substance responsible for such unique germination behavior has yet to be identified. Hence we attempted to purify this substance. One thousand g of dried silkworm pupae was subjected to methanol extraction, followed by methanolysis, two different solvent partitions, and three different column chromatographies. A total of 12.4 mg of substance was obtained in the active fraction. The substance obtained exhibited an activity more than 46,000 times higher than that of the methanol extract. The substance was detected as a single peak on Sephadex LH20 column chromatography and as a single band on high-performance thin-layer chromatography. These data indicate that the concentrated fraction contained a high-purity substance.
    Download PDF (260K)
  • Kenji MORI
    2010 Volume 74 Issue 3 Pages 595-600
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    A mixture of the four stereoisomers of 1,7-dimethylnonyl propanoate, the female sex pheromone of the western corn rootworm (Diabrotica virgifera virgifera LeConte), was synthesized in four different ways by employing one of the following four reactions as the key step: (i) cross metathesis using the Grubbs I catalyst, (ii) cross metathesis using the Grubbs II catalyst, (iii) alkylation of an alkynide anion, and (iv) Grignard coupling in the presence of dilithium tetrachlorocuprate. Although the cross metathesis approaches enabled two short syntheses (4 or 6 steps) of the pheromone to be achieved, the cheapest and most efficient synthesis was possible via Grignard coupling to give the desired pheromone in a 40% overall yield based on 2-methyl-1-butanol (8 steps).
    Download PDF (136K)
Organic Chemistry Notes
Biochemistry & Molecular Biology Regular Papers
  • Chang-Dong WANG, Jian-Guo HUANG, Xuan GAO, Yi LI, Shi-Yi ZHOU, Xu YAN, ...
    2010 Volume 74 Issue 3 Pages 488-493
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Prostate cancer (PCA) is the most common invasive malignancy and the second leading cause of cancer-related death in males. The present study investigated the effects of fangchinoline (Fan), an important compound in Stephania Tetradra S. Moore (Fenfangji) with pain-relieving, blood pressure-depressing, and antibiotic activities, on human PCA. It was found that Fan inhibited human prostate cancer cell lines (PC3) cell proliferation in a dose- and time-dependent manner. Studies of cell-cycle progression showed that the anti-proliferative effect of Fan was associated with an increase in the G1/S phase of PC3 cells. Western blot results indicated that Fan-induced G1/S phase arrest was mediated through inhibition of cyclin-regulated signaling pathways. Fan induced p27 expression and inhibited cyclin D and proliferating cell nuclear antigen (PCNA) expression in PC3 cells. Increased exposure time to Fan caused apoptosis of PC3 cells, which was associated with up-regulation of pro-apoptotic proteins Bax and caspase 3, and down-regulation of anti-apoptotic protein Bcl-2. Furthermore, Fan had anti-tumorigenic activity in vivo, including reduction of tumor volume and pro-apoptotic and anti-proliferative effects in a PC3 nude mouse xenograft. Taking all this together, it can be concluded that Fan is an effective anti-proliferative agent that modulates cell growth regulators in prostate cancer cells.
    Download PDF (268K)
  • Yasunori NAGAMATSU, Shoutarou OKAMURA, Hiroyuki SAITOU, Tetsuyuki AKAO ...
    2010 Volume 74 Issue 3 Pages 494-498
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Bacillus thuringiensis strain M019, non-pathogenic to lepidopteran and dipteran insects, produces a parasporal inclusion that consists of three 84-kDa Cry proteins (CPs). CP78A and CP78B, which exhibit 83.5% amino acid identity, were new variants of the previously reported HeLa cell-killing protein (parasporin-1). CP84 was a novel CP showing low-level homology, of 21.9% (56.4% similarity), with the insecticidal Cry2 toxin. In vitro solubilization with dithiothreitol at pH 10.2 and limited hydrolysis with trypsin resulted in the removal of N-terminal portions of the CPs and their activation. The 70-kDa proteins (15- and 55-kDa fragments) from CP78A and CP78B and the 73-kDa protein (14- and 59-kDa fragments) from CP84 exhibited varying degrees of cytocidal activity preferentially toward human hepatocyte cancer HepG2 cells and uterus cervix cancer HeLa cells causing cell swelling or the formation of vacuoles in the cytoplasm. These toxins appeared to attack an identical target on human cells.
    Download PDF (260K)
  • Ahmed Ragaa Nour IBRAHIM, Seiji KAWAMOTO, Minori NISHIMURA, Syunka PAK ...
    2010 Volume 74 Issue 3 Pages 504-509
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Japanese cedar (Cryptomeria japonica) pollen is a major cause of seasonal rhinitis and conjunctivitis in Japan, and an understanding of its full allergen repertoire is prerequisite for the development of future molecular diagnostics and immunotherapeutic strategies. Here we report the identification of a new C. japonica pollen IgE-binding antigen (CJP-8) homologous to lipid transfer proteins (LTPs), a class of plant cross-reactive allergens found in foods, latex, and pollen grains. The cjp-8 cDNA encodes a 165-amino acid polypeptide possessing the conserved eight cysteines characteristic of plant LTP family members. Escherichia coli-expressed recombinant CJP-8 (r-CJP-8) reacted with IgE antibody from Japanese cedar pollinosis patients at a 37.5% frequency (6/16).
    Download PDF (1041K)
  • Nobuhiro ABURAI, Mami YOSHIDA, Motoko OHNISHI, Ken-ichi KIMURA
    2010 Volume 74 Issue 3 Pages 548-552
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Sanguinarine, a plant alkaloid, was identified as a potent and specific protein phosphatase (PP) 2C inhibitor. It inhibited PP2C competitively with respect to α-casein (Ki=0.68 μM) and showed selectivity for PP2C as compared with PP1, PP2A, and PP2B in vitro. In vivo, sanguinarine showed cytotoxicity toward human promyelocytic leukemia cell line HL60, with an IC50 value of 0.37 μM, and induced apoptosis through a caspase-3/7-dependent mechanism involving the phosphorylation of p38, a PP2Cα substrate. The apoptosis activity induced by sanguinarine was partially inhibited by a p38 inhibitor, SB203580, and was involved in the phospho-p38 protein in HL60 cells.
    Download PDF (130K)
  • Tae Kyung HYUN, Libor HAVLICEK, Miroslav STRNAD, Thomas ROITSCH
    2010 Volume 74 Issue 3 Pages 553-557
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    A number of compounds have been reported to be specific inhibitors of protein kinases mediated by structural-based selectivity, but the development of specific inhibitors has not yet been addressed in plant science. Here we tested C2, C6, and N9-trisubstituted purines to determine the basic relationship between their chemical structure and inhibitory activity versus a plant mitogen-activated protein kinase (MAPK). Modification of substitution at positions C2 and N9 caused increased inhibitory activity of 6-benzylaminopurine analogs. In the case of 6-isopentenyladenine derivatives, the addition of a methyl group at position N9 caused at least 2-fold increased inhibitory activity, as compared with the addition of an isopropyl group. The data indicate that the selectivity and potency of inhibitors can be improved by modification of the chemical structure, suggesting that trisubstituted purines are powerful tools for probing biological processes and understanding the physiological roles of MAPK signaling.
    Download PDF (157K)
  • Shun OGAWA, Tetsuya SHIMIZU, Tsubasa KIMURA, Kazunori UTOH, Toshikatsu ...
    2010 Volume 74 Issue 3 Pages 558-562
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Supplementary material
    The Pro-form (Pro-EndoPG I) of Stereum purpureum endopolygalacturonase I has a unique C-terminal region (pro-sequence) that is lacking in PGs of other origins. Mature EndoPG I purified from the culture filtrate of this fungus does not have the 44-amino-acid pro-sequence present in Pro-EndoPG I. We expressed Pro-EndoPG I in Escherichia coli and examined its activity. It was found that Pro-EndoPG I had no PG activity, but that PG activity was acquired after the degradation of part of the pro-sequence with V8 protease. These results suggest that the pro-sequence inactivates auto-PG activity. No similar characteristic has been reported for any glycoside hydrolase. We then constructed EndoPG I mutants and identified two Glu residues, E364 and E366, that were related to auto-inactivation. A test involving injection of the enzyme into apple trees showed that Pro-EndoPG I induced the same silver-leaf symptoms as mature EndoPG I.
    Download PDF (164K)
  • Yasuyuki SAKAMOTO, Kiichi SATO, Mitsuru ABO, Takehiko TSUKAHARA, Takeh ...
    2010 Volume 74 Issue 3 Pages 569-572
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Supplementary material
    We developed a large cell culture surface with a nanostripe structure by paving polydimethylsiloxane (PDMS) replicas of a glass mold. The stripe structure has a height of 180 nm and top width of 500 nm with 400-nm intervals between stripes. Human stomach cancer SH-10-TC cells cultured on the surface changed their morphology to elongated shapes parallel to the nanostripes. In addition, cell motility parallel to the stripes was greatly enhanced. These findings strongly suggest that the nanostripe structure affected the cell physiology.
    Download PDF (303K)
  • Wataru SUMIYOSHI, Shin-ichi NAKAKITA, Kayo HASEHIRA, Nobumitsu MIYANIS ...
    2010 Volume 74 Issue 3 Pages 606-613
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Supplementary material
    We have reported a strategic procedure for the preparation of human-type N-linked oligosaccharides targeting hen egg white and yolk. To determine whether the technique is applicable to other avian species, we performed comparative analysis of N-linked oligosaccharides derived from eggs of other pheasant species. Our investigation of the principal oligosaccharides resulted in several major findings: (i) Glycan profiles as well as total yields were different between species and tissues (egg white and yolk). (ii) A common feature of egg white glycans is agalactosylated, hybrid-type, and complex-type oligosaccharides containing bisecting GlcNAc as major components. (iii) Egg yolk of pheasant species contained α2-6sialylated, biantennary complex-type oligosaccharides as major components. (iv) Egg yolk of Japanese pheasant and golden pheasant contained unusual persialylated oligosaccharides. Our results suggest that pheasant egg glycomes are significantly different from other avian species, although some common features are present.
    Download PDF (169K)
  • Li-mei CHEN, Hiroya YURIMOTO, Kun-zhi LI, Izumi ORITA, Motomu AKITA, N ...
    2010 Volume 74 Issue 3 Pages 627-635
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Formaldehyde (HCHO) is an air pollutant suspected of being carcinogenic and a cause of sick-house syndrome. Microorganisms called methylotrophs, which can utilize reduced C1 compounds such as methane and methanol, fix and assimilate HCHO, whereas most plants are unable to assimilate HCHO directly. We found that a bacterial formaldehyde-fixing pathway (ribulose monophosphate pathway) can be integrated as a bypass to the Calvin-Benson cycle in transgenic Arabidopsis thaliana and tobacco by genetic engineering. These plants showed enhanced tolerance to HCHO and enhanced capacity to eliminate gaseous HCHO by fixing it as a sugar phosphate. Our results provide a novel strategy for phytoremediation of HCHO pollution, and also represent the first step toward the production of plants that can assimilate natural gas-derived C1 compounds.
    Download PDF (403K)
Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Biology Communication
  • Yuzy MATSUO, Hayafumi KISHIMOTO, Tomitaka HORIUCHI, Katsuhiro TANAE, M ...
    2010 Volume 74 Issue 3 Pages 685-689
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Supplementary material
    Gap-repair cloning for plasmid construction in budding yeast is very effective and often used. In contrast, the same method is not widely used in fission yeast, because of a shortage of information on it. Here we describe simple and effective gap-repair cloning for plasmid construction using short tracts of flanking homology. By this method, we combined concentrated DNA fragments with short (20 bp) tracts of flanking homology with the marker gene or the pre-existing gene module. In addition, we found that this method can be applied to one-step cloning of multiple DNA fragments to construct a fusion gene.
    Download PDF (130K)
Food & Nutrition Science Regular Papers
  • Chang-Shin LIM, Eun-Young KIM, Hyun-Sam LEE, Yunjo SOH, Youngjoo SOHN, ...
    2010 Volume 74 Issue 3 Pages 477-483
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Cinnamomum cassia Blume (CC) is one of the world’s oldest natural spices, and is commonly used in traditional oriental medicine. We investigated the protective effect of ethanol extract from Cinnamomum cassia Blume (CCE) on the activation of hepatic stellate cells (HSCs). In addition, we examined the effects of CC powder in Sprague-Dawley rats with acute liver injury induced by dimethylnitrosamine (DMN). In vitro, HSC-T6 cells exhibit an activated phenotype, as reflected in their fibroblast-like morphology. CCE significantly reduced the expression of alpha-smooth muscle actin (α-SMA), connective tissue growth factor (CTGF), transforming growth factor beta (TGF-β1), and tissue inhibitor of metalloproteinase-1 (TIMP-1). In vivo, the results were significantly protected by CC powder in the serum total protein, albumin, total-bilirubin, direct-bilirubin, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and alkaline phosphatase (ALP). We suggest that CC inhibits fibrogenesis, followed by HSC-T6 cell activation and increased restoration of liver function, ultimately resulting in acute liver injury.
    Download PDF (423K)
  • Takayuki WATANABE, Keishi HATA, Kazuyuki HIWATASHI, Kazuyuki HORI, Nao ...
    2010 Volume 74 Issue 3 Pages 499-503
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    We investigated in this study the anti-obesity effect of an extract of Petasites japonicus (a culinary vegetable from Eastern Asia) on a murine adipocyte cell line (3T3-L1) and on diet-induced obesity-prone mice. An ethanol extract of P. japonicus. (PJET) suppressed 3T3-L1 preadipocyte differentiation; however, a hot water extract of P. japonicus (PJHW) exhibited no effect on cell differentiation. PJET significantly attenuated three adipogenetic transcription factors, peroxisome proliferator-activated receptor γ2, CCAAT/enhancer-binding protein and sterol regulatory element-binding protein 1C, at the mRNA level and suppressed the gene expression of fatty acid synthetase. An experiment with diet-induced obesity-prone C57BL/6J mice showed that PJET lowered the body weight gain and visceral fat tissue accumulation, and ameliorated the plasma cholesterol concentration. These findings suggest that P. japonicus might be an effective food against obesity.
    Download PDF (192K)
  • Noriko HAYASHI, Tetsuo IIDA, Takako YAMADA, Kazuhiro OKUMA, Isao TAKEH ...
    2010 Volume 74 Issue 3 Pages 510-519
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    This clinical study was conducted to investigate the safety and effect of D-psicose on postprandial blood glucose levels in adult men and women, including borderline diabetes patients. A randomized double-blind placebo-controlled crossover experiment of single ingestion was conducted on 26 subjects who consumed zero or 5 g of D-psicose in tea with a standard meal. The blood glucose levels at fasting and 30, 60, 90, and 120 min after the meal were compared. The blood glucose level was significantly lower 30 and 60 min after the meal with D-psicose (p<0.01, p<0.05), and a significant decrease was also shown in the area under the curve (p<0.01). The results suggest that D-psicose had an effect to suppress the postprandial blood glucose elevation mainly in borderline diabetes cases. A randomized double-blind placebo-controlled parallel-group experiment of long-term ingestion was conducted on 17 normal subjects who took 5 g of D-psicose or D-glucose with meals three times a day for 12 continuous weeks. Neither any abnormal effects nor clinical problems caused by the continuous ingestion of D-psicose were found.
    Download PDF (142K)
  • Pongsak RATTANACHAIKUNSOPON, Parichat PHUMKHACHORN
    2010 Volume 74 Issue 3 Pages 520-524
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Foods contaminated with Salmonella enterica serovar Typhi are a mojor cause of typhoid fever, leading to public health problems and economic losses worldwide. Nisin and ρ-cymene were tested in this study for their antimicrobial activity against S. Typhi at 4 °C and 37 °C. Nisin and ρ-cymene, when used separately, did not inhibit the bacterium at either temperature. A synergistic antimicrobial effect between both compounds was observed when they were used simultaneously. This synergism was greater at 37 °C than at 4 °C. The lowest concentrations of nisin and ρ-cymene required for complete inhibition of S. Typhi at 37 °C were 0.3 ppm and 1.5 ppm, respectively, and 0.3 ppm and 2.5 ppm at 4 °C. The potential of nisin and ρ-cymene to control an S. Typhi population on ready-to-eat Thai-style pork sausage was also examined. The compounds were able to eliminate the contaminating bacterium with concentrations depending on the bacterial cell number on the food.
    Download PDF (99K)
  • Shuhei YAMAMOTO, Natsuka MIKAMI, Masatomo MATSUNO, Takashi HARA, Sumik ...
    2010 Volume 74 Issue 3 Pages 525-530
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    The effects of a high-pressure treatment on the IgE-specific binding activity and structural changes to bovine gamma globulin (BGG), a beef allergen, were investigated. The allergenicity of pressure-treated BGG was also evaluated. We found that the IgE-specific binding activity and allergenicity of BGG were decreased by the high-pressure treatment. Almost no significant change in secondary structure was apparent for pressurized BGG, but a change in the tertiary structure was detected. The decreased IgE-specific binding activity and allergenicity of pressurized BGG were probably due to changes in the tertiary structure caused by pressurization. The results of this study suggest that a high-pressure treatment would be an effective food-processing technique to reduce the allergenicity of BGG.
    Download PDF (176K)
  • Yo OMATA, Yasukazu YOSHIDA, Etsuo NIKI
    2010 Volume 74 Issue 3 Pages 531-535
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    The oxidation of lipids, proteins, and DNA induced by reactive oxygen species has been implicated in the development of various diseases, and the role of antioxidants has received much attention. Free-radical scavenging antioxidants play an important role in the defense network in vivo, and assessment of the capacity of antioxidants has been the subject of extensive studies and controversy, but there is no universal method by which antioxidant capacity can be measured accurately. In the present study, the assessment of the antioxidant capacity of natural fruit extracts was examined for radical scavenging and inhibition of lipid peroxidation. It was found that the capacity of fruit extracts for scavenging of both hydrophilic and lipophilic free radicals and for antioxidation can be assessed from the effect on the probe decay and the inhibition of plasma lipid peroxidation respectively. The importance of these two factors in the assessment of antioxidant capacity is discussed.
    Download PDF (122K)
  • Toshiyuki NAKAMURA, Noritoshi KITAMOTO, Toshihiko OSAWA, Yoji KATO
    2010 Volume 74 Issue 3 Pages 536-540
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    In a previous study we prepared monoclonal antibody against allyl isothiocyanate (AITC)-modified lysine (Lys), and found that AITC reacted with Lys under physiological conditions in vitro (T. Nakamura et al., Chem. Res. Toxicol., 22, 536–542 (2009)). In the present study, antibodies against benzyl isothiocyanate (ITC), 6-methylsulfinylhexyl ITC and phenethyl ITC modified protein were prepared, and the respective monoclonal antibodies, B6C9, 6MS3D10, and PE3A10 were obtained. These antibodies were applied to ITC detection in food using shredded Wasabia japonica (wasabi) and ground Carica papaya (papaya) seed by trapping ITC with biotin-labeled bovine serum albumin. ITC formation from the wasabi and papaya seed samples was confirmed using the antibodies in a dose-dependent manner. These antibodies might be applicable in identifying food-derived ITC.
    Download PDF (195K)
  • Kosuke MURAKAMI, Sayaka SUZUKI, Naohito AOKI, Tetsuya OKAJIMA, Daita N ...
    2010 Volume 74 Issue 3 Pages 541-547
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Noroviruses (NoVs), which cannot be grown in cell culture, are a major infectious agent of gastroenteritis. An in vitro assay system was established for the evaluation of NoV binding to enterocytes using virus-like particles (VLPs) produced in a baculovirus system expressing a NoV VP1 capsid protein. After confirmation of the purity by MS analysis, VLPs were incubated with human intestinal Caco-2 cells. NoV VLPs were detected clearly by confocal laser microscopy only on a certain population of Caco-2 cells, and were semi-quantified by immunoblotting of cell lysates. Then the suppressive effect of pasteurized bovine colostrum was analyzed on the VLP binding to Caco-2 cells by immunoblotting. The colostrum reduced VLP binding in a dose-dependent manner, at about 50% suppression with 12.5 μg of the colostral proteins. Furthermore, the colostrum contained IgG antibodies reacting to VLPs, suggesting that cross-reactive antibodies in the bovine colostrums block human NoV binding to intestinal cells.
    Download PDF (395K)
  • Toshiyuki AKACHI, Yasuyuki SHIINA, Takumi KAWAGUCHI, Hirokazu KAWAGISH ...
    2010 Volume 74 Issue 3 Pages 573-578
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    To evaluate the protective effects of fruit juices against D-galactosamine (GalN)-induced liver injury, lyophilized fruit juices (total 12 kinds) were fed to rats for 7 d, and then we evoked liver injury by injecting GalN. The juice of camu-camu (Myrciaria dubia) significantly suppressed GalN-induced liver injury when the magnitude of liver injury was assessed by plasma alanine aminotransferase and aspartate aminotransferase activities, although some other juices (acerola, dragon fruit, shekwasha, and star fruit) also tended to have suppressive effects. An active compound was isolated from camu-camu juice by solvent fractionation and silica gel column chromatography. The structure was determined to be 1-methylmalate. On the other hand, malate, 1,4-dimethylmalate, citrate, and tartrate had no significant effect on GalN-induced liver injury. It is suggested that 1-methylmalate might be a rather specific compound among organic acids and their derivatives in fruit juices in suppressing GalN-induced liver injury.
    Download PDF (266K)
  • Ichiro SHIRASUGI, Miyuki KAMADA, Takashi MATSUI, Yoichi SAKAKIBARA, Mi ...
    2010 Volume 74 Issue 3 Pages 579-582
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Sulforaphane is a compound widely present in consumed vegetables, particularly broccoli. Previous studies have demonstrated that sulforaphane has many physiological effects including anti-cancer, anti-oxidation, and detoxification. In this study, we found that sulforaphane inhibited melanogenesis and tyrosinase expression. The inhibitory effect of 5 μM sulforaphane on melanogenesis was determined to be equivalent to that of 100 μM arbutin. In addition, sulforaphane induced phosphorylated extracellular signal-regulated kinase (ERK) and inhibited phosphorylated p38. It has been reported that the phosphorylated mitogen-activated protein (MAP) kinase family (ERK and p38) controls tyrosinase expression. Our data indicate that sulforaphane inhibited melanogenesis and tyrosinase expression by affecting the phosphorylated MAP kinase family. These findings indicate that sulforaphane might be an effective skin-whitening agent.
    Download PDF (106K)
  • Rongchun WANG, Tze Loon NEOH, Takashi KOBAYASHI, Yasuhito MIYAKE, Asao ...
    2010 Volume 74 Issue 3 Pages 601-605
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    The degradation kinetics of glucuronic acid (GlcA) under subcritical conditions from 160 to 200 °C was studied in a continuous tubular reactor. The formation of glucuronolactone (GlcL) during the treatment of GlcA in subcritical water was substantiated by ESI-TOF-MS and 1H NMR. The degradation of GlcA consisted of the reversible conversion of GlcA to GlcL and the irreversible degradation of the two compounds. The changes in the concentrations of GlcA and GlcL with residence time could be described by first-order kinetics. Higher temperatures accelerated the degradation of GlcA, and thus resulted in rises in the pH value. The degradation reaction of GlcL under the same conditions was also investigated. The activation energy of the reverse hydrolysis of GlcA to GlcL and that of the hydrolysis of GlcL to GlcA were determined to be 88.5 and 63.2 kJ/mol respectively. The enthalpy change in the reversible conversion between GlcA and GlcL was 25.4 kJ/mol.
    Download PDF (153K)
  • Masatoshi KUBOTA, Yuhi SAITO, Takehiro MASUMURA, Takehisa KUMAGAI, Rei ...
    2010 Volume 74 Issue 3 Pages 614-619
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Rice prolamin, constituting type-I protein body (PB-I), is indigestible and causes deterioration of rice protein nutritional quality. In this study, the in vivo digestibility of rice protein isolates was investigated by tracing their intraluminal transit in the gastrointestinal (GI) tract of rats by western blotting and by observing the structures excreted in the feces by electron microscopy. Two types of rice protein isolates, produced by alkali extraction (AE-RP) and by starch degradation (SD-RP), were compared. The protein patterns in the isolates were similar, but their digestion in the GI-tract showed striking differences. In the AE-RP group, 13-kDa prolamin (13P) quickly disappeared in the lower GI tract and was not excreted in the feces. By contrast, in the SD-RP group, 13P accumulated massively and nearly intact PB-Is were excreted. These results indicate that the in vivo digestibility of prolamin can be improved by alkali extraction through structural changes to it.
    Download PDF (188K)
  • Motoko OARADA, Miki IGARASHI, Tsuyoshi TSUZUKI, Katsuhiko KAMEI, Katsu ...
    2010 Volume 74 Issue 3 Pages 620-626
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    We investigated the effects of high protein intake on host resistance to Paracoccidioides brasiliensis. Two-d fasted mice were infected with P. brasiliensis and refed on diets with three different levels (54%, 20%, and 5%) of casein. The mice refed the 54% casein diet showed reduced antifungal activity in the spleen and liver as compared with the mice refed the 5% or the 20% casein diet. After infection, increases in spleen and liver mRNA levels of myeloperoxidase, cathepsin-G, and elastase-2 were more profound in the mice refed the 54% casein diet as compared with the mice refed the 5% or the 20% casein diet. Infected mice refed the 54% casein diet exhibited greater interferon (IFN)-γ production in the spleen and liver and higher levels of thiobarbituric acid reactive substances (TBARSs) in the liver as compared with those refed the 5% casein diet. These results indicate that high protein intake impairs host resistance to P. brasiliensis.
    Download PDF (138K)
Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Tatsuro HAGI, Miho KOBAYASHI, Masaru NOMURA
    2010 Volume 74 Issue 3 Pages 484-487
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Variations in milk microflora caused by changes in the cow feeding environment (from inside to outside grazing) were analyzed using a molecular-based approach comprising denaturing gradient gel electrophoresis and real-time PCR. After 8 d of outside grazing, changes in milk microflora were observed. Denaturing gradient gel electrophoresis analysis showed that the predominant bacterial group in the milk belonged to the Lactobacillus species during the experimental period, whereas the genus Staphylococcus gained in numbers during the outside grazing period in addition to Lactobacillus. To investigate the quantitative dynamics of staphylococci, real-time PCR was performed using staphylococcal-specific primers. Real-time PCR analysis revealed that the population of staphylococci increased during the outside grazing period. Our combined denaturing gradient gel electrophoresis and real-time PCR approach enables precise monitoring of the dynamics of both total bacteria and specific bacterial species in milk. Our results provide information on grazing management and the manufacture of dairy products.
    Download PDF (103K)
  • Kaihei OKI, Kenji WASHIO, Daigo MATSUI, Shinichi KATO, Yoshihiko HIRAT ...
    2010 Volume 74 Issue 3 Pages 583-589
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Urolith, which consists of dirty yellow-colored attachments on the toilet bowl, is associated with a variety of odorous chemicals, including ammonia, and causes disadvantages in daily life. Although largely it is derived from microorganisms, little is known about the microbial processes underlying the formation of urolith. In order to gain insight into the types and the activities of microorganisms present in urolith, culturable bacteria were isolated, identified, and physiologically characterized. One of the isolates exhibited higher ability to produce ammonia when it was grown in artificial urine medium. Phylogenetic and physiological analyses indicated that this strain (T-02) belonged to a new group of Staphylococcus species, showing combined phenotypes as between S. lentus and S. xylosus. T-02 exhibited high urease activity and was capable of growing in the urinary condition by forming robust biofilms. The results of this study indicate that T-02 has successfully adapted itself to the environment of urolith.
    Download PDF (332K)
  • Kazuaki SATO, Yuichi KATO, Ayabi FUKAMACHI, Masahiro NOGAWA, Goro TAGU ...
    2010 Volume 74 Issue 3 Pages 636-640
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    A stable bacterial community expressing strong chitinolytic activity was constructed by mixing and cultivating chitinolytic bacteria collected from different natural sources. The DNA fragment pattern, after PCR-denaturing gradient gel electrophoresis (DGGE) targeting 16S rRNA genes using total DNA prepared from whole cells, indicated that the community was composed of four dominant bacterial species. All four species were isolated on agar medium, and one strain, SAY3, was deduced to be a novel species belonging to a new genus based on the 16S rRNA nucleotide sequence. The other strains showed high similarity in their 16S rRNA sequences to those of previously identified bacteria (Acinetobacter and Microbacterium). Strain SAY3 degraded and utilized larger particles of chitin faster than the community, indicating that it plays an important role in the chitin degradation conferred by the community.
    Download PDF (115K)
  • Yohei KATSUYAMA, Yutaka HIROSE, Nobutaka FUNA, Yasuo OHNISHI, Sueharu ...
    2010 Volume 74 Issue 3 Pages 641-645
    Published: March 23, 2010
    Released: March 23, 2010
    [Advance publication] Released: March 07, 2010
    JOURNALS FREE ACCESS
    Curcuminoids, natural products in the rhizome of turmeric, show various biological activities, including antioxidant and antitumor activities. For this reason, curcuminoids have been focused on as potential pharmaceuticals. Exogenous supplementation with various carboxylate precursors in genetically engineered Escherichia coli cells carrying an artificially assembled pathway for curcuminoid biosynthesis led to the production of 17 unnatural curcuminoids.
    Download PDF (139K)
feedback
Top