Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 71 , Issue 12
Showing 1-38 articles out of 38 articles from the selected issue
Analytical Chemistry Regular Paper
  • Choong KIM, In Hye LEE, Kangsun LEE, Sung Shin RYU, Sang Ho LEE, Kyu-J ...
    2007 Volume 71 Issue 12 Pages 2985-2991
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    A multi-well chip (MWC) is described by which mouse embryonic carcinoma (EC) stem cells form a comparatively more rapid and uniform embryoid body (EB) over the conventional hanging drop (HD) method. The newly developed MWC consists of an array of extruded through-holes, each of which holds a droplet of the cell suspension. The study found that the small curvature radius of the droplet in the MWC improved the EB formation rate of a hanging drop from 70% to 98%. Furthermore, the EBs formed by the MWC were uniformly round in shape regardless of the number of suspended cells ranging from 0.5×103 to 20×103. The ratio of beating colonies from the MWC was over 2-fold larger than that from HD. The experiments demonstrate that the MWC will be a valuable experimental tool for robust and reproducible EB-based differentiation of a defined number of ES cells.
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Analytical Chemistry Note
  • Katsuhiro MATSUI, Isao KAWAJI, Yuichi UTSUMI, Yoshiaki UKITA, Toshifum ...
    2007 Volume 71 Issue 12 Pages 3098-3101
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    Microfluid filters were fabricated, which possessed 2,100 cylindrical through-bores (φ40 μm) in 200 μm-thickness polymethylmethacrylate (PMMA) sheets (φ3 mm), by deep X-ray lithography using synchrotron radiation. To evaluate the microfluid filters as a device for an immunoassay, we bound the goat anti-mouse immunogloblin G (IgG) antibody to the surface of the filters, and set the filters between reaction vessels stacked vertically in a microreactor. An enzyme-linked immunosorbent assay (ELISA) of mouse IgG using the goat anti-mouse IgG/horseradish-peroxidase (HRP) conjugate indicated that mouse IgG could be quantitatively detected in the range of 0–100 ng/ml, demonstrating the applicability of vertical microfluidic operation to the immunoassay.
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Organic Chemistry Regular Papers
  • Takuya SUGAHARA, Satoshi YAMAUCHI, Ai KONDO, Fumi OHNO, Siori TOMINAGA ...
    2007 Volume 71 Issue 12 Pages 2962-2968
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    The first stereoselective synthesis of meso-secoisolariciresinol is reported. A comparison of the cytotoxic and immunosuppressive activity between meso-secoisolariciresinol and optically active secoisolariciresinols was similarly performed for the first time. Both enantiomers of secoisolariciresinol accelerated IgM production, although meso-secoisolariciresinol did not affect IgM production. Only meso-secoisolariciresinol showed cytotoxic activity.
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  • Mino NAKAYA, Hiroki OGURI, Kosaku TAKAHASHI, Eri FUKUSHI, Kenji WATANA ...
    2007 Volume 71 Issue 12 Pages 2969-2976
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    Our interest on engineering non-ribosomal synthetase responsible for SW-163 biosynthesis prompted us to determine the relative and absolute configuration of antitumor cyclic depsipeptide SW-163s. We first isolated and identified SW-163 homologs D, F and G as known compounds UK-63598, UK-65662 and UK-63052, respectively. Both enantiomers of the unusual constitutive amino acid, N-methylnorcoromic acid, were synthesized in chiral forms starting from (R)- and (S)-1,2-propanediol. The hydrolyzate of SW-163D, a major constituent of this family, was converted with Marfey’s reagent, 1-fluoro-2,4-dinitrophenyl-5-L-alanine-amide (L-FDAA), and the resulting mixture of amino acid derivatives was subjected to an LC/MS analysis. Compared with authentic samples, the analytical data unambiguously show that SW-163D consisted of L-Ala, D-Ser and (1S, 2S)-N-methylnorcoronamic acid. The remaining stereochemistry of the N-methylcysteine moieties was determined from NOE data.
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Organic Chemistry Note
  • Tae TSUKAGOSHI, Tetsuo TOKIWANO, Hideaki OIKAWA
    2007 Volume 71 Issue 12 Pages 3116-3121
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    Mutilin (4) and deoxy analogues 2 and 3 are biosynthetic precursors of pleuromutilin (1) in the later stage of biosynthesis. Precursors 2 and 3 are required for studies on the oxygenation steps in biosynthesis, and were synthesized from readily available 1 via 4 by deoxygenation of the hydroxy groups. Feeding experiments with the 2H-labeled precursors confirmed their microbial conversion into 1.
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Organic Chemistry Communication
  • Hiroshi NOZAKI, Ken-ichiro HAYASHI, Naoki NISHIMURA, Hiroshi KAWAIDE, ...
    2007 Volume 71 Issue 12 Pages 3127-3130
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    Momilactones A (1) and B (2), which have been identified as phytoalexins in rice, were isolated from extracts of the moss Hypnum plumaeforme. This is the first isolation and identification of momilactones as allelochemicals from a bryophyte. H. plumaeforme produces considerable amounts of momilactones (isolated yield: 8.4 mg/Kg plant for 1; 4.2 mg/Kg for 2). EtOAc extracts from H. plumaeforme and 2 showed growth inhibitory activity against angiosperms, moss, and liverwort plants. On the other hand, the growth of H. plumaeforme was insensitive to its extract and 2. Our finding suggests that momilactones play an important role as allelochemicals in this moss.
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Biochemistry & Molecular Biology Regular Papers
  • Takashi TAMURA, Kosuke TOMIMATSU, Yoshinori KATAKURA, Makiko YAMASHITA ...
    2007 Volume 71 Issue 12 Pages 2871-2875
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    Human monoclonal antibodies have great potential for use in the treatment of various diseases. We have established an in vitro immunization protocol for inducing antigen-specific antibody production from human peripheral blood mononuclear cells (PBMCs). In the in vitro immunization protocol, PBMCs are pretreated with L-leucyl-L-leucine methyl ester (LLME) to remove suppressive cells, and are sensitized and cultured with a soluble antigen in the presence of IL-2, IL-4 and muramyl dipeptide for 8 d, and then an antigen-specific antibody is produced. In this study, we examined the novel possibility of an in vitro immunization protocol, specifically, whether LLME-treated PBMCs can be sensitized with a peptide antigen to produce an anti-peptide antibody. The results indicate that antigen-specific immune responses were elicited by a peptide antigen derived from rice allergen, a cholera toxin B subunit, and TNF-α as a sensitizing antigen in in vitro immunization. These results suggest that the in vitro immunization protocol is applicable in the generation of an anti-peptide antibody against various antigens, including food allergens, foreign antigens, and self-antigens.
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  • Tomohiro MEGA
    2007 Volume 71 Issue 12 Pages 2893-2904
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    The presence of typical plant-type N-glycans (eg, M3FX, Gn2M3FX, and Lea2M3FX) in mosses, ferns, and other organisms was examined to determine which plant initially acquired glycosyltransferases to produce plant-type N-glycans during organic evolution. No M3FX-type N-glycan was detected in lichens (Cladonia humilis) or in any one of the three preland plants Enteromorpha prolifera, Ulva pertusa Kjellman, and Chara braunii Gmelin. In Bryophyta, M3FX-type N-glycan was detected at trace amounts in Anthocerotopsida (hornworts) and at certain amounts in Bryopsida (mosses), but not in Hepaticopsida (liverworts). Lea2M3FX was detected in some Bryopsida of relatively high M3FX content. Most Tracheophyta (ferns and higher plants) contained the three typical M3FX-type glycans as the main N-glycans in different ratios. These results suggest that organisms acquired xylosyltransferase and fucosyltransferase during the development of mosses from liverworts, and that later all plants retained both enzymes. Bryopsida have also obtained galactosyltransferase and fucosyltransferase to synthesize the Lea antigen.
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  • Hiroshi MIZOGUCHI, Kimie TANAKA-MASUDA, Hideo MORI
    2007 Volume 71 Issue 12 Pages 2905-2911
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    Supplementary material
    We developed a simple method of generating markerless deletions in the Escherichia coli chromosome. The method consists of two recombination events stimulated by λ Red recombinase. The first recombination replaced a target region with a marker cassette and the second then eliminated the marker cassette. The marker cassette included an antibiotic resistant gene and a negative selection marker (Bacillus subtilis sacB). Since sacB makes E. coli sensitive to sucrose, a markerless deletion strain was successfully selected using its sucrose-resistant phenotype. To stimulate these recombination events, 1-kbp homologous sequences adjacent to the target region were connected to both ends of the marker cassette or connected to each other by PCR. The average efficiency of the recombinations was 24% and 93% respectively. Eliminating the marker cassette with a fragment including an additional sequence, insertion was also possible. This markerless deletion method should be useful in creating a highly modified E. coli chromosome.
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  • Ayumi HIDAKA, Yoshinori HAMAJI, Takayuki SASAKI, Shun’ichiro TAN ...
    2007 Volume 71 Issue 12 Pages 2921-2926
    Published: December 23, 2007
    Released: December 23, 2007
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    Bifidobacteria are nonpathogenic, anaerobic domestic bacteria with health-promoting properties for the host. In our previous study, Bifidobacterium longum (B. longum) were found to be localized selectively and to proliferate within solid tumors after systemic application. Additionally, B. longum transformed by shuttle-plasmid including the cytosine deaminase (CD) gene expressed active CD, converted the prodrug 5-fluorocytosine (5-FC) to 5-fluorouracil (5-FU). We also demonstrated antitumor efficacy with a transformant of B. longum in rats. In this study, we found that Bifidobacterium breve (B. breve), the smallest species of human-derived bifidobacterium, expressed the exogenous transgene (CD), that CD enzymatic activity in the transformant of B. breve was much higher, and that the segregational stability of the plasmid was greater than that of B. longum. Thus, numerous transformants of B. breve were detected solely in the tumors after systemic administration. We consider the transformant of B. breve to be more beneficial in our enzyme/prodrug therapy.
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  • H. Reynaldo LÓPEZ-MIRABAL, Jakob R. WINTHER, Morten C. KIELLAND ...
    2007 Volume 71 Issue 12 Pages 2934-2942
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    The conditional ero1-1 mutant, deficient in the ER-localized PDI oxidase Ero1p, is blocked in disulfide bond formation under restrictive conditions, such as high temperature, lack of oxygen, or high concentrations of membrane-permeant thiols. Previous studies of the physiological consequences of the ero1-1 mutation were carried out in a leu2 mutant. The ero1-1 leu2 strain does not grow in standard synthetic complete medium at 30 °C, a defect that can be remedied by increasing the L-leucine concentration in the medium or by transforming the ero1-1 leu2 strain with the LEU2 wild-type allele. In addition, the LEU2 gene can partially complement the growth impairment at 37 °C of the ero1-1 leu2 mutant. The leucine transporter Bap2p exhibits a dramatic decrease in stability in an ero1-1 strain, which may account for the pronounced leucine demand observed in the ero1-1 leu2 mutant.
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  • Katsura KOJIMA, Yoshihiko KUWANA, Hideki SEZUTSU, Isao KOBAYASHI, Keir ...
    2007 Volume 71 Issue 12 Pages 2943-2951
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    We constructed a new plasmid vector for the production of a modified silk fibroin heavy chain protein (H-chain) in the transgenic silkworm. The plasmid (pHC-null) contained the promoter and the 3′ region of a gene encoding the H-chain and the coding regions for the N-terminal domain and the C-terminal domain of the H-chain. For the model protein, we cloned a foreign gene that encoded EGFP between the N-terminal domain and the C-terminal domain in pHC-null and generated transgenic silkworms that produced a modified H-chain, HC-EGFP. Transgenic silkworms produced HC-EGFP in the posterior part of silk gland cells, secreted it into the lumen of the gland, and produced a cocoon with HC-EGFP as part of the fibroin proteins. N-terminal sequencing of HC-EGFP localized the signal sequence cleavage site to between positions A(21) and N(22). These results indicate that our new plasmid successfully produced the modified H-chain in a transgenic silkworm.
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  • Akihito HARADA, Hiroshi YAGI, Akira SAITO, Hiroyuki AZAKAMI, Akio KATO
    2007 Volume 71 Issue 12 Pages 2952-2961
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    The positively charged lysine at the C-terminals of three long α-helices (5-15, 25-35, and 88-99) was replaced with alanine (K13A, K33A, K97A) or aspartic acid (K13D, K33D, K97D) in hen lysozyme by genetic engineering. The denaturation transition point (Tm) and Gibbs energy change ΔG of the mutant lysozymes decreased remarkably, suggesting that the positive charge at the C-terminals of helices is involved in the stabilization of the helix dipole. On the other hand, the non-charged asparagine at the N-terminal of the long α-helices (25-35 and 88-99) was replaced with negatively charged aspartic acid (N27D and N93D). The Tm and ΔG of N27D increased, suggesting that the dipole moment of the N-terminal of the helices is diminished by replacement with negatively charged amino acid strengthening the stability of the helices. The stabilities of those hen egg white lysozymes mutated at the N- or C-terminal sites of the three long α-helices were related with their secretion amounts in yeast (Pichia pastoris). The secretion amounts of these mutant lysozymes in yeast were closely correlated with their stability.
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  • Minoru TAKEDA, Yohei MIYANOIRI, Takeshi NOGAMI, Kanae ODA, Tatsuya SAI ...
    2007 Volume 71 Issue 12 Pages 2992-2998
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    The sheath of Sphaerotilus natans is composed of cysteine-rich peptide and polysaccharide moieties. The polysaccharide was prepared by treating the sheath with hydrazine, and was determined to be a mucopolysaccharide containing β-D-GlcA, β-D-Glc, α-D-GalN, and β-D-GalN. To elucidate the structure of the peptide, the sheath was labeled with a thiol-selective fluorogenic reagent, 4-(aminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole. Enantiomeric determination of the S-derivatized Cys in the fluorescent sheath suggested that it contained L-Cys mainly. Fluorescent cysteinylglycine was detected in the partial acid hydrolysate of the fluorescent sheath. The sheath-degrading enzyme secreted by Paenibacillus koleovorans produced a fluorescent disaccharide-dipeptide composed of GalN, Gly, and N-acetylated Cys from the fluorescent sheath. The disaccharide and dipeptide moieties were found to be connected by an amide bond. Based on these results, the sheath was deduced to be formed by association of a mucopolysaccharide modified with N-acetyl-L-cysteinylglycine.
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  • Jun-Won YUN, Young-Kyung KIM, Byoung-Seok LEE, Chae-Wook KIM, Jin-Sook ...
    2007 Volume 71 Issue 12 Pages 2999-3006
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    This study was designed to determine whether dietary epigallocatechin-3-gallate (EGCG), the most abundant catechin polyphenol in green tea, can protect the liver from cytochrome P450 2E1 (CYP2E1)-dependent alcoholic liver damage. Compared with an ethanol group, when EGCG was present in the ethanol diet, the formation of a fatty liver was significantly reduced and the serum aspartate transaminase (AST) and alanine transaminase (ALT) levels were much lower. Ethanol treatment significantly elevated hepatic CYP2E1 expression while simultaneously reducing hepatic phospho-acetyl CoA carboxylase (p-ACC) and carnitine palmitoyl-transferase 1 (CPT-1) levels. While EGCG markedly reversed the effect of ethanol on hepatic p-ACC and CPT-1 levels, it had no effect on the ethanol-induced elevation in CYP2E1 expression. EGCG prevents ethanol-induced hepatotoxicity and inhibits the development of a fatty liver. These effects were associated with improvements in p-ACC and CPT-1 levels. The use of EGCG might be useful in treating patients with an alcoholic fatty liver.
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  • Saemi KATO, Akiko SHIMIZU-IBUKA, Kiyoshi MURA, Akiko TAKEUCHI, Chiyoko ...
    2007 Volume 71 Issue 12 Pages 3007-3013
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    An α-amylase secreted by Pichia burtonii 15-1 isolated from a traditional starter murcha of Nepal, named Pichia burtonii α-amylase (PBA), was studied. The gene was cloned and its nucleotide sequence was determined. PBA was deduced to consist of 494 amino acid residues. It shared certain degrees of amino acid sequence identity with other homologous proteins: 60% with Schwanniomyces occidentalis α-amylase, 58% with Saccharomycopsis sp. α-amylase, and 47% with Taka-amylase A from Aspergillus oryzae. A three-dimensional structural model of PBA generated using the known three-dimensional structure of Taka-amylase A as a template suggested high structural similarity between them. Kinetic analysis revealed that the Km values of PBA were lower than those of Taka-amylase A for the oligosaccharides. Although the kcat values of PBA were lower than those of Taka-amylase A for the oligosaccharide substrates, the kcatKm values of PBA were higher.
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  • Hiroko MORI, Hideo IWAHASHI
    2007 Volume 71 Issue 12 Pages 3014-3018
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    To clarify the effect of superoxide dismutase (SOD) on the formation of hydroxyl radical in a standard reaction mixture containing 15 μM of xanthone, 0.1 M of 5,5-dimethyl-1-pyrroline N-oxide (DMPO), and 45 mM of phosphate buffer (pH 7.4) under UVA irradiation, electron paramagnetic resonance (EPR) measurements were performed. SOD enhanced the formation of hydroxyl radicals. The formation of hydroxyl radicals was inhibited on the addition of catalase. The rate of hydroxyl radical formation also slowed down under a reduced oxygen concentration, whereas it was stimulated by disodium ethylenediaminetetraacetate (EDTA) and diethyleneaminepentaacetic acid (DETAPAC). Above findings suggest that O2, H2O2, and iron ions participate in the reaction. SOD possibly enhances the formation of the hydroxyl radical in reaction mixtures of photosensitizers that can produce O2−·.
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  • Takaaki KUBOTA, Jyunpei SHIMONO, Chie KANAMEDA, Yoshikazu IZUMI
    2007 Volume 71 Issue 12 Pages 3033-3040
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    The first thermophilic α-oxoamine synthase family enzyme was identified. The gene (ORF TTHA1582), which is annotated to code putative α-oxoamine synthase family enzymes, 7-keto-8-aminopelargonic acid (KAPA) synthase (BioF, 8-amino-7-oxononanoate synthase, EC 2.3.1.47) and 2-amino-3-ketobutyrate CoA ligase (KBL, EC 2.3.1.29), in a genomic database, was cloned from an extreme thermophile, Thermus thermophilus, and overexpressed in Escherichia coli. The recombinant TTHA1582 protein was purified and characterized. It exhibited activity of BioF, which catalyzes the condensation of pimeloyl-CoA and L-alanine to produce a biotin intermediate KAPA, CoASH, and CO2 with pyridoxal 5′-phosphate as a cofactor. The protein is a dimer with a subunit of 43 kDa that shows an amino acid sequence identity of 35% with E. coli BioF. The optimum temperature and pH were about 70 °C and about 6.0. The enzyme showed high thermostability at temperatures of up to 70 °C for 1 h, and a half-life of 1 h at 80 °C. Thus the TTHA1582 protein was found to have the highest optimum temperature and thermostablility of the α-oxoamine synthase family enzymes so far reported. Substrate specificity experiments revealed that it was also able to catalyze the KBL reaction, which used acetyl-CoA and glycine as substrates, and that enzyme activity was seen with the following combinations of substrates: acetyl-CoA and glycine, L-alanine, or L-serine; pimeloyl-CoA and L-alanine, glycine, or L-serine; palmitoyl-CoA and L-alanine. This suggests that the recombinant TTHA1582 protein has broad substrate specificity, unlike the reported mesophilic enzymes of the α-oxoamine synthase family.
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  • Yasuyuki FUJITA, Satoka MITA, Hokuto OHTSUKA, Hirofumi AIBA
    2007 Volume 71 Issue 12 Pages 3041-3047
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    The lcf1+ gene, which encodes a long chain fatty acyl-CoA synthetase, is necessary for the maintenance of viability after entry into the stationary phase in Schizosaccharomyces pombe. In this study, we analyzed a paralogous gene, SPBP4H10.11c (named lcf2+), and we present evidence that the gene encodes a new fatty acyl-CoA synthetase. The enzyme preferentially recognized myristic acid as a substrate. A Δlcf2 mutant showed increased viability after entry into the stationary phase in SD medium. A Δlcf1Δlcf2 double mutant showed a severe decrease in long-chain fatty acyl-CoA synthetase activity and a rapid loss of viability after entry into the stationary phase. These results suggest that fatty acid utilization and/or metabolism is important to determine viability in the stationary phase.
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  • Ryuichiro TANAKA
    2007 Volume 71 Issue 12 Pages 3055-3062
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    In addition to serine (L:D = 68:32), methionine sulfoxide (MSO), L-methionine sulfone (L-MSO2), and disodium γ-cyclic di-L-glutamate were identified in a methanol extract of Bombyx mori L. pupae. MSO was isolated in a diastereomeric mixture of L(+)- and D(+)-MSO in a ratio of 99:1. The presence of these compounds in other developmental stages, including eggs, larvae (1st, 4th, 5th, and mature 5th instar), adults, and excrement (feces and urine) was investigated. The L(+)-isomer of MSO was present in extracts of the 1st and 5th instar larvae, adults, and eggs, but was not detected in feces or urine. The D(+)-isomer was found only in pupal stage extracts, and was excreted into the meconium with L(+)-isomer. L-MSO2 and γ-cyclic di-L-glutamate were not detected at other insect life stages or in the insect excrement. γ-Cyclic di-L-glutamate is thought be produced due to blockage of the glutamate synthetic pathway (glutamine synthetase) by L-MSO2 and Mg2+. The biochemical role of L-MSO2 during the pupal life stage remains unknown, but importantly, the stage-specific expression suggests that it is a candidate molecule for the induction of diapause.
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  • Yoshimasa ITO, Takenori WATANABE, Shunsuke NAGATOMO, Taiichiro SEKI, S ...
    2007 Volume 71 Issue 12 Pages 3082-3089
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    Recently we found a small hepatocyte-specific protein, annexin A3 (AnxA3), in fractionated adult rat hepatocytes. Here we describe the results of an in vivo demonstration of AnxA3-expressing cellular phenotypes in the liver with 2-acetylaminofluoren (2-AAF)/carbon tetrachloride (CCl4)-injury. In association with an elevation of alanine amino transferase (ALT) and aspartic acid amino transferase (AST) activities, hepatic AnxA3 mRNA increased markedly. AnxA3-positive cells were detected in clustered cells present in or emerging from the pericentral region. These albumin-expressed cells were histologically similar to cells expressing CD34, a hematopoietic cell marker protein. The number of clusters decreased in the days following CCl4 treatment, and annexin-negative, but albumin-positive, oval cells appeared. We concluded that the agent-induced liver defect initially recruits bone marrow-derived cells, and that it promotes differentiation of these cells into AnxA3-positive cells, followed by emergence of the oval cells, which might have a role in the restitution of the damaged liver.
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Biochemistry & Molecular Biology Notes
Biochemistry & Molecular Communication
  • Yoshiyuki KASAHARA, Yuki TAKAYANAGI, Teruo KAWADA, Keiichi ITOI, Katsu ...
    2007 Volume 71 Issue 12 Pages 3122-3126
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    We analyzed temperature homeostasis in oxytocin-deficient (Oxt−⁄−) mice and found that Oxt−⁄− mice exhibited lower body temperatures than wild-type animals when they were exposed to cold. Oxt−⁄− mice also showed slightly more weight gain, but there were no obvious differences in the morphology of white and brown adipose tissues as between wild-type and Oxt−⁄− mice. In cold-exposed conditions, oxytocin neurons containing c-Fos immunoreactivity existed in the paraventricular nucleus of the hypothalamus.
    These results suggest that the central oxytocin neurons constitute part of the thermoregulatory system involved in maintaining body temperature in cold environments.
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Food & Nutrition Science Regular Papers
  • Eun Kyoung KIM, Eun-Young KIM, Phil-Dong MOON, Jae-Young UM, Hyung-Min ...
    2007 Volume 71 Issue 12 Pages 2886-2892
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    Lithospermi radix (LR, Borraginaceae, the root of Lithospermum erythrorhizon Siebold. et Zuccarinii) is used in herbal medicine to treat such conditions as eczema, skin burns and frostbite. This study investigates the effects of LR on the anti-allergy mechanism. LR inhibited the release of histamine from rat peritoneal mast cells by compound 48/80 in a dose-dependent manner. LR orally administered at 6.59 mg/100 g also inhibited the anti-DNP IgE-induced passive cutaneous anaphylaxis reaction. LR inhibited the PMA plus A23187-induced increase in IL-6, IL-8, and TNF-α expression in HMC-1 cells. In addition, LR also inhibited nuclear factor-kappa B (NF-κB) activation and IκB-α degradation. These results show that LR had an inhibitory effect on the atopic allergic reaction. Furthermore, the in vivo and in vitro anti-allergic effect of LR suggests possible therapeutic applications of this agent for inflammatory allergic diseases.
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  • Toshihisa OHNO, Makoto TOMATSU, Kazuki TOEDA, Naganori OHISA
    2007 Volume 71 Issue 12 Pages 2912-2920
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
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    The textures of cooked rice prepared from aged rice grains and their improvement by reducing agents were investigated. For aged rice that was stored for 5 months without air by the operation of a vacuum packing machine, the stickiness/hardness ratio of cooked rice was as low as that of aged rice stored in air. The results of electrophoresis showed that oxidation of proteins in the former was advanced to the same degree as in the latter. The stickiness/hardness ratios of the aged rice were increased by the addition of sodium sulfite, cysteine, and dithiothreitol to the cooking water. Sodium sulfite, cysteine, and dithiothreitol cleave disulfide bonds to sulfhydryl groups. Therefore, cleaving disulfide bonds to sulfhydryl groups improved the texture. The addition of them to the cooking water also increased the extractable solids at the time of heating. Hence cleaving disulfide bonds to sulfhydryl groups must increase extractable solids. Consequently, the gelatinized paste layer thickened and the thick paste layer softened the cooked rice.
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  • Seung-Hyun LEE, Young Heui KIM, Heui-Jong YU, Nam-Suk CHO, Tae-Hyun KI ...
    2007 Volume 71 Issue 12 Pages 2927-2933
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
    JOURNALS FREE ACCESS
    In order to improve the solubility and bioavailability of a soy isoflavone extract (IFE), inclusion complexes (IFE-β-CD) of the isoflavone extract with β-cyclodextrin (β-CD) were prepared and studied for their solubility and bioavailability. The aqueous solubility of the complexes of IFE with β-CD (2.0 mg/ml) was about 26 times that of IFE itself (0.076 mg/ml). The same dosages of IFE and IFE-β-CD were orally administered to SD rats (Sprague-Dawley) on an isoflavone glycoside (IFG) basis (daidzin, genistin and glycitin), and the plasma concentrations of daidzein, genistein and glycitein were measured over time to estimate the average AUC (area under the plasma concentration versus time curve) of the isoflavones. After the oral administration, the AUC values for daidzein, genistein and glycitein were 340, 11 and 28 μg·min/ml, respectively. In contrast, the respective AUC values after the administration of IFE-β-CD were 430, 20 and 48 μg·min/ml. The bioavailability of daidzein in IFE-β-CD was increased to 126% by the formation of inclusion complexes with β-CD, compared with that in IFE. Furthermore, the bioavailability of genistein and glycitein in IFE-β-CD formulation was significantly higher by up to 180% and 170%, respectively, compared with that of IFE p=0.008 and p=0.028, respectively). These results show that the absorption of IFE could be improved by the complexation of IFE with β-CD (IFE-β-CD).
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  • Hiromi SAWAMURA, Tsutomu FUKUWATARI, Katsumi SHIBATA
    2007 Volume 71 Issue 12 Pages 2977-2984
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
    JOURNALS FREE ACCESS
    To determine the effects of excess biotin administration on growth and water-soluble vitamin metabolism, weaning rats were fed on a 20% casein diet containing 0.00002% biotin, or same diet with 0.04, 0.08, 0.10, 0.20, 0.50, 0.80 or 1.0% added biotin for 28 days. More than 0.08% biotin administration decreased the food intake and body weight gain compared with the levels in control rats. An accumulation of biotin in such tissues as the liver, brain and kidney increased in a dose-dependent manner, and the both bound and free biotin contents in the liver also increased in a dose-dependent manner. An excess administration of biotin did not affect the urinary excretion of other water-soluble vitamins, suggesting no effect on the metabolism of other water-soluble vitamins. The results of the food intake and body weight gain indicated that the lowest observed adverse effect level for young rats was 79.2 mg/kg body weight/day, while the no observed adverse effect level was 38.4 mg/kg/day. These results suggested immediately setting a tolerable upper intake level for biotin.
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  • Kenji DEJIMA, Akihiro OHSHIMA, Takaaki YANAI, Reiko YAMAMOTO, Ryoji TA ...
    2007 Volume 71 Issue 12 Pages 3019-3025
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
    JOURNALS FREE ACCESS
    We investigated the efficacy of the polysaccharide derived from black currant, named cassis polysaccharide (CAPS), for inhibiting Japanese cedar pollinosis symptoms and improving quality of life by a randomized double-blind, placebo-controlled trial in 2006. A total of 28 subjects were enrolled in the study, and 10 subjects in each group completed the trial. Although there was no significant difference between the CAPS and placebo group in the weekly mean value of any symptom in the daily symptom diary at any time, a smaller degree of final symptom aggravation was found in the CAPS group. Significant aggravation of the score was finally observed in the placebo group with inferior conch swelling and with sneezing, itchy nose, itchy eye and watery eye in the Japan rhino-conjunctivitis quality of life questionnaire assessment, while the changes observed in the CAPS group were not significant. In conclusion, our findings clearly indicate that CAPS would be useful as a food supplement in assisting the treatment of Japanese cedar pollinosis.
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  • Shintaro ICHIKAWA, Rei FUJII, Daisuke FUJIWARA, Yutaka KOMIYAMA, Tsune ...
    2007 Volume 71 Issue 12 Pages 3026-3032
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
    JOURNALS FREE ACCESS
    Although lactic acid bacteria (LAB) affect the immune system, for example, having an anti-allergic effect, little is known about the actual mechanisms of immune modulation. Toll-like receptors (TLRs) recognize conserved microbial molecular patterns, and are presumed to be involved in the recognition of LAB. However, there are few detailed reports examining the relationships between TLR and LAB. We measured here production of IL-12, a cytokine considered to play an important role in anti-allergic effects, induced by Lactobacillus paracasei strain KW3110 and other typical LAB by cells from TLR2-, TLR4-, TLR9- and myeloid differentiation factor 88 (MyD88)-deficient mice. Unexpectedly, similar cytokine production from wild-type and TLR2-, 4- and 9-deficient mice was observed. In contrast, cells from MyD88-deficient mice failed to respond to stimulation with LAB. It is therefore concluded that although LAB, including strain KW3110, are not likely to be recognized by TLR2, 4 or 9, MyD88 is essential for the response to these bacteria.
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  • In Suk SON, Ji Hyun KIM, Ho Yong SOHN, Kun Ho SON, Jong-Sang KIM, Chon ...
    2007 Volume 71 Issue 12 Pages 3063-3071
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
    JOURNALS FREE ACCESS
    Diosgenin (a steroidal saponin of yam) has long been used as a raw material for the industrial production of steroid drugs, and reported to have a hypocholesterolemic effect by suppressing cholesterol absorption and increasing cholesterol secretion. Oxidative stress has been suggested as a main risk factor in the development of atherosclerosis. The aim of this study is to investigate the possible hypolipidemic and antioxidative effect of diosgenin on rats fed with a high-cholesterol diet supplemented with either 0.1% or 0.5% diosgenin for 6 weeks. We measured the lipid profile in the plasma and liver, lipid peroxidation and antioxidative enzyme activities in the plasma, erythrocyte and gene expression of antioxidative enzymes in the liver, and the oxidative DNA damage in lymphocytes. Diosgenin showed a decrease in the plasma and hepatic total cholesterol levels, but increased the plasma high-density lipoprotein (HDL) cholesterol level. Erythrocyte TBARS and lymphocyte DNA damage measured by the comet assay were decreased in the diosgenin supplemented group. Furthermore, diosgenin feeding enhanced the resistance to lymphocyte DNA damage caused by an oxidant challenge with H2O2. The antioxidative enzyme activities were also affected by diosgenin supplementation. Total superoxide dismutase (SOD) in the plasma and liver, glutathione peroxidase (GSH-Px) in erythrocytes, and catalase (CAT) in erythrocytes and liver were significantly increased in the 0.5% diosgenin group. The expression of antioxidative enzymes was up-regulated by diosgenin, the expression of GSH-Px being the highest in the 0.5% diosgenin group. These results suggest that diosgenin could be a very useful compound to control hypercholesterolemia by both improving the lipid profile and modulating oxidative stress.
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Food & Nutrition Science Notes
Food & Nutrition Science Communication
  • Soichi TANABE, Makiko HASE, Takeo YANO, Masahiko SATO, Tatsuya FUJIMUR ...
    2007 Volume 71 Issue 12 Pages 3131-3135
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
    JOURNALS FREE ACCESS
    A rapid real-time quantitative PCR method to detect trace amounts of pork, chicken, beef, mutton, and horseflesh in foods was developed. The primers and TaqMan MGB (minor groove binder) probes were designed on the gene encoding cytochrome b for the specific detection of each species. The limit of quantification of this method was found to be 100 fg/μl of each mitochondrial DNA in 10 ng/μl of the wheat mitochondrial DNA matrix. The calculated R2 values of the standard curves for the five species ranged between 0.994 and 0.999. This method would be particularly useful in the detection of hidden meat mince in processed foods, which would verify food labeling and gain consumers’ trust.
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Microbiology & Fermentation Technology Regular Papers
  • Goro TAKATA, Wayoon POONPERM, Devendar RAO, Akane SOUDA, Tomoe NISHIZA ...
    2007 Volume 71 Issue 12 Pages 2876-2885
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
    JOURNALS FREE ACCESS
    The L-arabinose metabolic gene cluster, araA, araB, araD, araG, araH and araR, encoding L-arabinose isomerase (L-AI) and its accessory proteins was cloned from Mycobacterium smegmatis SMDU and sequenced. The deduced amino acid sequence of araA displayed highest identity with that of Bacillus subtilis (52%). These six genes comprised the L-arabinose operon, and its genetic arrangement was similar to that of B. subtilis. The L-AI gene (araA), encoding a 501 amino acid protein with a calculated molecular mass of 54,888 Da, was expressed in Escherichia coli. The productivity and overall enzymatic properties of the recombinant L-AI were almost same as the authentic L-AI from M. smegmatis. Although the recombinant L-AI showed high substrate specificity, as did L-AI from other organisms, this enzyme catalyzed not only isomerization of L-arabinose-L-ribulose and D-galactose-D-tagatose but also isomerization of L-altrose-L-psicose and L-erythrulose-L-threose. In combination with L-AI from M. smegmatis, L-threose and L-altrose can be produced from cheap and abundant erythritol and D-fructose respectively, indicating that this enzyme has great potential for biological application in rare sugar production. Transcription analysis using various sugars revealed that this enzyme was significantly induced not only by L-arabinose and D-galactose but also by L-ribose, galactitol, L-ribulose, and L-talitol. This different result of transcription mediated by sugars from that of E. coli suggests that the transcriptional regulation of araA from M. smegmatis against sugar is loose compared with that from E. coli, and that it depends on the hydroxyl configuration at C2, C3 and C4 positions of sugars.
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  • Pushpakiran GULLAPALLI, Goro TAKATA, Wayoon POONPERM, Devendar RAO, Ke ...
    2007 Volume 71 Issue 12 Pages 3048-3054
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
    JOURNALS FREE ACCESS
    D-Psicose, a new alternative sweetener, was produced from allitol by microbial oxidation of the newly isolated strain Enterobacter aerogenes IK7. Cells grown in tryptic soy broth medium (TSB) supplemented with D-mannitol at 37 °C were found to have the best oxidation potential. The cells, owing to broad substrate specificity, oxidized various polyols (tetritol, pentitol, and hexitol) to corresponding rare ketoses. By a resting cell reaction, 10% of allitol was completely transformed to the product D-psicose, which thus becomes economically feasible for the mass production of D-psicose. Finally, the product was crystallized and confirmed to be D-psicose by analytical methods.
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  • Yutaka HAYASHI, Hiroyasu ONAKA, Nobuya ITOH, Haruo SETO, Tohru DAIRI
    2007 Volume 71 Issue 12 Pages 3072-3081
    Published: December 23, 2007
    Released: December 23, 2007
    [Advance publication] Released: December 07, 2007
    JOURNALS FREE ACCESS
    KS-505a (longestin), produced by Streptomyces argenteolus, has a unique structure that consists of a tetraterpene (C40) skeleton, to which a 2-O-methylglucuronic acid and an o-succinyl benzoate moiety are attached. It is a novel inhibitor of calmodulin-dependent cyclic-nucleotide phosphodiesterase, which is representative of a potent anti-amnesia drug. As a first step to understanding the biosynthetic machinery of this unique and pharmaceutically useful compound, we cloned a KS505a biosynthetic gene cluster. First we searched for a gene encoding octaprenyl diphosphates, which yielded a C40 precursor by PCR, and four candidate genes were obtained. Among these, one was confirmed to have the expected enzyme activity by recombinant enzyme assay. On the basis of an analysis of the flanking regions of the gene, a putative KS-505a biosynthetic gene cluster consisting of 24 ORFs was judged perhaps to be present on a 28-kb DNA fragment. A gene disruption experiment was also employed to confirm that the cluster indeed participated in KS-505a biosynthesis. This is believed to be the first report detailing the gene cluster of a cyclized tetraterpenoid.
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Microbiology & Fermentation Technology Note
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