Bioscience, Biotechnology, and Biochemistry
Online ISSN : 1347-6947
Print ISSN : 0916-8451
Volume 70 , Issue 4
Showing 1-43 articles out of 43 articles from the selected issue
Organic Chemistry Note
  • Masayuki OGAWA, Jyunichi KOYANAGI, Aiko SUGAYA, Tadashi TSUDA, Hiromi ...
    2006 Volume 70 Issue 4 Pages 1009-1012
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    We investigated the cytotoxic activity of 2-substituted naphtho[2,3-b]furan-4,9-diones. We have previously synthesized 33 types of 2-substituted and related compounds, and the cytotoxic activity of these compounds was then examined by a KB cell culture assay. 2-(3-Furanoyl)benzoic acids and 1,4-naphthoquinones had no activity. 2-Acetyl-4,9-dimethoxynaphtho[2,3-b]furan 4 showed low activity. However, parent naphtho[2,3-b]furan-4,9-dione 2 and most 2-substituted derivatives exhibited cytotoxic activity. The parent structure was therefore for cytotoxicity. 2-Formylnaphtho[2,3-b]furan-4,9-dione 11 had particularly potent activity (ED50=0.09 μg/ml).
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Biochemistry & Molecular Biology Regular Papers
  • Hoyeun KIM, Pil-Joon PARK, Hyun-Ju HWANG, So-Young LEE, Man-Ho OH, San ...
    2006 Volume 70 Issue 4 Pages 768-773
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Transgenic plants overexpressing AXR3/IAA17 were impaired in root growth. Specifically, they exhibited severe defects in lateral root and root hair development similar to the root phenotypes of epi-brassinolide (epiBL)-treated wild-type plants. Here, we investigated the involvement of AXR3/IAA17 gene expression in brassinosteroid (BR)-regulated root development. Exogenous epiBL application significantly induced expression of the AXR3/IAA17 gene as well as several Aux/IAA genes, such as AXR2/IAA7, SLR/IAA14, and IAA28. We analyzed the transcription levels of several Aux/IAA genes related to root development in the BR signaling mutant bri1 and the BR biosynthesis mutant det2. AXR3/IAA17 gene expression was significantly decreased in bri1 plants. In det2 plants, expression of AXR3/IAA17 slightly decreased. This in turn suggests that epiBL induced these Aux/IAA genes, and that these induced gene products might function as factors in root development. Furthermore, AXR3/IAA17 might be involved in the BR signaling pathway, suggesting an intersection node of BR-auxin signaling in root development.
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  • Su Young HONG, Chang Long AN, Kye Man CHO, Sun Mi LEE, Yong Hee KIM, M ...
    2006 Volume 70 Issue 4 Pages 798-807
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    A third bgl operon containing bglE, bglF, bglI, and bglA was isolated from Pectobacterium carotovorum subsp. carotovorum LY34 (Pcc LY34). The sequences of BglE, BglF, and Bgll were similar to those of the phosphotransferase system (PTS) components IIB, IIC, and IIA respectively. BglF contains important residues for the phosphotransferase system. The amino acid sequence of BglA showed high similarity to various 6-phospho-β-glucosidases and to a member of glycosyl hydrolase family 1. Sequence and structural analysis also revealed that these four genes were organized in a putative operon that differed from two operons previously isolated from Pcc LY34, bglTPB (accession no. AY542524) and ascGFB (accession no. AY622309). The transcription regulator for this operon was not found, and the EII complexes for PTS were encoded separately by three genes (bglE, bglF, and bglI). The BglA enzyme had a molecular weight estimated to be 57,350 Da by SDS–PAGE. The purified β-glucosidase hydrolyzed salicin, arbutin, ρNPG, ρNPβG6P, and MUG, exhibited maximal activity at pH 7.0 and 40 °C, and displayed enhanced activity in the presence of Mg2+ and Ca2+. Two glutamate residues (Glu178 and Glu378) were found to be essential for enzyme activity.
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  • Akie TOYOTA, Hiroshi AKIYAMA, Mitsunori SUGIMURA, Takahiro WATANABE, H ...
    2006 Volume 70 Issue 4 Pages 821-827
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Because the labeling of grains and feed- and foodstuffs is mandatory if the genetically modified organism (GMO) content exceeds a certain level of approved genetically modified varieties in many countries, there is a need for a rapid and useful method of GMO quantification in food samples. In this study, a rapid detection system was developed for Roundup Ready® Soybean (RRS) quantification using a combination of a capillary-type real-time PCR system, a LightCycler® real-time PCR system, and plasmid DNA as the reference standard. In addition, we showed for the first time that the plasmid and genomic DNA should be similar in the established detection system because the PCR efficiencies of using plasmid DNA and using genomic DNA were not significantly different. The conversion factor (Cf) to calculate RRS content (%) was further determined from the average value analyzed in three laboratories. The accuracy and reproducibility of this system for RRS quantification at a level of 5.0% were within a range from 4.46 to 5.07% for RRS content and within a range from 2.0% to 7.0% for the relative standard deviation (RSD) value, respectively. This system rapidly monitored the labeling system and had allowable levels of accuracy and precision.
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  • Tamao INO, Makoto HATTORI, Tadashi YOSHIDA, Shunji HATTORI, Keiji YOSH ...
    2006 Volume 70 Issue 4 Pages 865-873
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Soluble egg shell membrane protein (SEP) prepared from the egg shell membrane by performic acid oxidation and pepsin digestion was applied to prepare a membrane conjugated with pepsin-solubilized collagen (PSC) by cross-linking with water-soluble carbodiimide. SEP enabled a conjugated membrane to be constructed with a well-developed network structure having thicker collagen fibrils and higher stability than the PSC membrane alone, as indicated by reduced solubility and collagenase-digestion, increased denaturation temperature, and superior flexibility. The SEP-PSC membrane (SEP:PSC of 1:1, w/w) had lower sweatiness than the PSC membrane. Fibroblasts and keratinocytes adhered to the SEP-PSC-coated wells (SEP:PSC of 1:10, w/w) as a fundamental model of an artificial skin similar to that to the PSC-coated wells due to similar expression level of several cell-adhesion proteins. An SEP-PSC coating accelerated the cell growth of fibroblasts, whereas the cell growth of keratinocytes did not change, or decreased slightly due to more rapid differentiation indicated by a more substantial expression of differentiation marker proteins than a PSC-coating without SEP.
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  • Hiromi TAKARADA, Yoshiaki KAWANO, Kouichi HASHIMOTO, Hiroshi NAKAYAMA, ...
    2006 Volume 70 Issue 4 Pages 881-889
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Nitrile hydratase (NHase) from Rhodococcus sp. N771 is a non-heme iron enzyme having post-translationally modified cysteine ligands, αCys112-SO2H and αCys114-SOH. We replaced αGln90, which is conserved in all known NHases and involved in the hydrogen-bond network around the catalytic center, with glutamic acid or asparagine. The kcat of αQ90E and αQ90N mutants decreased to 24% and 5% that of wild type respectively, but the effect of mutations on Km was not very significant. In both mutants, the αCys114-SOH modification appeared to be responsible for the catalysis as in native NHase. We crystallized the nitrosylated αQ90N mutant and determined its structure at a resolution of 1.43 Å. The structure was basically identical to that of native nitrosylated NHase except for the mutated site and its vicinity. The structural difference between native and αQ90N mutant NHases suggested the importance of the hydrogen bond networks between αGln90 and the iron center for the catalytic activity.
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  • Noriko HATTORI, Hiroshi NOMOTO, Satoshi MISHIMA, Shinsuke INAGAKI, Mas ...
    2006 Volume 70 Issue 4 Pages 897-906
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    An extract of royal jelly (RJ) induced processes from cultured rat pheochromocytoma PC12 cells. Active components were isolated, and identified as adenosine monophosphate (AMP) and AMP N1-oxide. AMP N1-oxide was more than 20 times as active as AMP, judging from the minimal concentration to elicit activity. AMP N1-oxide was thought to be responsible for about half of the process-forming activity of whole RJ. Chemically-synthesized AMP N1-oxide was active similarly to the molecule purified from RJ, confirming AMP N1-oxide as the active entity. AMP N1-oxide also suppressed proliferation of PC12 cells and stimulated expression of neurofilament M, a specific protein of mature neurons, demonstrating the stimulatory activity of AMP N1-oxide to induce neuronal differentiation of PC12 cells. Pharmacological experiments suggested that AMP N1-oxide actions are mediated by adenyl cyclase-coupled adenosine receptors, including A2 A. Thus AMP N1-oxide is a key molecule that characterizes RJ, and is not found in natural products other than RJ.
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  • Yasushi MAKINO, Kaoru OMICHI
    2006 Volume 70 Issue 4 Pages 907-915
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Amylo-1,6-glucosidase from porcine brain was purified to homogeneity by ammonium sulfate fractionation, followed by sequential steps of liquid chromatography on DEAE-Sephacel, Sephacryl S-300, and Super Q. The purified enzyme had both maltooligosaccharide transferase and amylo-1,6-glucosidase activities within a single polypeptide chain, and the combination of these two activities removed the branches of phosphorylase limit dextrin. Based on these results, the purified enzyme was identified as a glycogen debranching enzyme (GDE). The molecular weight of the brain GDE was 170,000 by gel-filtration and 165,000 by reducing SDS–PAGE. The pH profile of maltooligosaccharide transferase activity coincided with that of the amylo-1,6-glucosidase activity (pH optimum at 6.0). The existence of GDE as well as glycogen phosphorylase in the brain explains brain glycogenolysis fully and supports the hypothesis that glycogen is a significant source of energy in this organ.
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  • Kwan-Yub KANG, Jung-Hwan PARK, In-Hwan LIM, Sung-Geun KIM, See-Hyoung ...
    2006 Volume 70 Issue 4 Pages 916-925
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    In this study, the Kringle V domain (Glu4225-Ser4310) of human apolipoprotein A, an antiangiogenic polypeptide, was expressed as a secreted form in Pichia pastoris, and was purified via a process consisting of three chromatographic steps. The chromatographically purified kringle V domain contained a C-terminal serine-deleted form and several high-molecular-weight forms, which were suspected to represent glycosylated derivatives. In order to remove these derivatives, we employed a crystallization process. The crystallization of kringle V resulted in an 85% recovery yield, and also resulted in the complete removal of the aforementioned high-molecular-weight forms. However, we were still able to detect a trace of the C-terminal serine-deleted form. The prepared Kringle V crystals were stable within a pH range of 7.0 to 8.0, and were completely dissolved by dilution, which is a crucial factor in the preparation of a highly concentrated formulation. The chromatogram of the crystallized kringle V on reversed-phase HPLC analysis was identical to that observed without crystallization. Also, we noted that the original anti-wound migration activities of the molecule toward human umbilical vein endothelial cells were completely retained.
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  • Yoshihiro AIBA, Makiko YAMASHITA, Yoshinori KATAKURA, Yuki FURUKAWA, S ...
    2006 Volume 70 Issue 4 Pages 966-970
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Pretreatment with L-leucyl-L-leucine methyl ester (LLME) is a prerequisite for peripheral blood mononuclear cells (PBMCs) to produce antigen-specific antibodies when sensitized with an antigen. Little information, however, is available regarding the mechanisms involved in LLME-induced augmentation of antibody production from PBMCs that are antigen sensitized. In the present study, we attempted to identify the genes involved in the suppression of antibody production from PBMCs that was not treated with LLME, but sensitized with an antigen. Using subtractive screening, we obtained 63 independent genes, including 17 EST genes, that are specific for LLME-nontreated PBMC. Among these genes, the expression of heavy chain ferritin (H-ferritin), CC chemokine ligand 18 (CCL18), and matrix metalloproteinase 12 (MMP12) were augmented in LLME-nontreated PBMCs, suggesting that inflammatory factors might be involved in the suppression of antibody production in LLME-nontreated PBMCs.
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  • Masahiro MATSUMIYA, Yasuyuki ARAKANE, Atsunobu HAGA, Subaratnam MUTHUK ...
    2006 Volume 70 Issue 4 Pages 971-979
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Three chitinase isozymes, HoChiA, HoChiB, and HoChiC, were purified from the stomach of the greenling, Hexagrammos otakii, by ammonium sulfate fractionation, followed by column chromatography on Chitopearl Basic BL-03 and CM-Toyopearl 650S. The molecular masses and pIs of HoChiA, HoChiB, and HoChiC are 62 kDa and pH 5.7, 51 kDa and pH 7.6, and 47 kDa and pH 8.8, respectively. Substrate specificities of these chitinases were compared with those of another fish stomach chitinase from the common mackerel, Scomber japonicus (SjChi), as well as two from the tobacco hornworm, Manduca sexta (MsChi535 and MsChi386). The efficiency parameters, kcatKm, toward glycolchitin for HoChiA and SjChi were larger than those for HoChiB and HoChiC. The relative activities of HoChiA and SjChi toward various forms of chitin were as follows: shrimp shell or crab shell α-chitin > β-chitin >> silkworm cuticle α-chitin. On the other hand, the relative activities of HoChiB and HoChiC were β-chitin >> silkworm α-chitin > shrimp and crab α-chitin. MsChi535 preferred silkworm α-chitin to shrimp and crab α-chitins, and no activity was observed toward β-chitin. MsChi386, which lacked the C-terminal linker region and the chitin-binding domain, did not hydrolyze silkworm α-chitin. These results demonstrate that fish and insect chitinases possess unique substrate specificities that are correlated with their physiological roles in the digestion of food or cuticle.
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  • Yoshihiro KOBAE, Masahiro MIZUTANI, Shoji SEGAMI, Masayoshi MAESHIMA
    2006 Volume 70 Issue 4 Pages 980-987
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Aquaporins mediate the movement of water across biomembranes. Arabidopsis thaliana contains 35 aquaporins that belong to four subfamilies (PIP, TIP, SIP, and NIP). We investigated their expression profiles immunochemically in suspension-cultured Arabidopsis thaliana cells during growth and in response to salt and osmotic stresses. Protein amounts of all aquaporins were much lower in cultured cells than in the plant tissues. This is consistent with the low water permeability of protoplasts from cultured cells. After treatment with NaCl, the protein amounts of PIP2;1, PIP2;2, and PIP2;3 in the cells increased several-fold, and those of TIP1;1 and TIP1;2, 15- and 3-fold respectively. PIP1 did not change under the stress. Cell death began after 19 d in culture, accompanied by marked accumulation of PIPs and TIPs and a gradual decrease in SIPs. Our results suggest the followings: (i) Accumulation of aquaporin isoforms was individually regulated at low levels in single cells. (ii) At least PIP2;2, PIP2;3, TIP1;1, and TIP1;2 are stress-responsive aquaporins in suspension cells. (iii) A sudden increment of several members of PIP2 and TIP1 subfamilies might be related to cell death.
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  • Tomokazu KAWASE, Shinya YOKOKAWA, Akihiro SAITO, Takeshi FUJII, Naoki ...
    2006 Volume 70 Issue 4 Pages 988-998
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Streptomyces coelicolor A3(2) has 13 chitinase genes encoding 11 family 18 and two family 19 chitinases. To compare enzymatic properties of family 19 chitinase and family 18 chitinases produced by the same organism, the four chitinases (Chi18bA, Chi18aC, Chi18aD, and Chi19F), whose genes are expressed at high levels in the presence of chitin, were produced in Eschericha coli and purified. The effect of pH on the hydrolytic activity was very different not only among the four chitinases but also among the substrates. The hydrolytic activity of Chi19F, family 19 chitinase, against soluble substrates was remarkably high as compared with three family 18 chitinases, but was the lowest against crystalline substrates among the four chitinases. On the contrary, Chi18aC, a family 18-subfamily A chitinase, showed highest activity against crystalline substrates. Only Chi19F exhibited significant antifungal activity. Based on these observations, the roles of family 19 chitinases are discussed.
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Biochemistry & Molecular Biology Notes
  • Hyun-Kyung LEE, Jai-Hyun KWON, Sang-Ha PARK, Chan-Wha KIM
    2006 Volume 70 Issue 4 Pages 1003-1005
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    The pulmonary route appears to be the most attractive alternative for non-invasive systemic delivery of insulin. We have shown the feasibility of insulin microcrystals as a long-acting formulation for pulmonary delivery. In this study, we examined the effects of adjuvant for pulmonary formulations of insulin, such as protamine, zinc, and glycerol. In an in vivo experiment with rats, only zinc enhanced the hypoglycemic effect of insulin microcrystals, with 17% of minimum reductions in blood glucose (%MRBG) and a 44% decrement in the blood glucose level (D%9h).
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  • Atsushi SHIMONAKA, Jinichiro KOGA, Yuko BABA, Tomoko NISHIMURA, Koichi ...
    2006 Volume 70 Issue 4 Pages 1013-1016
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    We examined the characteristics of family 45 endoglucanases (glycoside hydrolases family 45; GH45) from Mucorales belonging to Zygomycota in the use of textiles and laundry. The defibrillation activities on lyocell fabric of family 45 endoglucanases from Mucorales, such as RCE1 and RCE2 from Rhizopus oryzae, MCE1 and MCE2 from Mucor circinelloides, and PCE1 from Phycomyces nitens, were much higher than those of the other family 45 endoglucanases. By contrast, family 45 endoglucanases from Mucorales were less resistant to anionic surfactant and oxidizing agent, main components in detergents, than the other family 45 endoglucanases. RCE1 consists of two distinct modules, a catalytic module and a carbohydrate-binding module family 1 (CBM1), and these common specific characteristics were considered to due to the catalytic module, but not to the CBM1.
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  • Hikaru SUENAGA, Mika SATO, Masatoshi GOTO, Mariko TAKESHITA, Kensuke F ...
    2006 Volume 70 Issue 4 Pages 1021-1025
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Biphenyl dioxygenase (Bph Dox) catalyzes initial oxygenation in the bacterial biphenyl degradation pathway. Bph Dox in Pseudomonas pseudoalcaligenes KF707 is a Rieske type three-component enzyme in which a large subunit (encoded by the bphA1 gene) plays an important role in the substrate specificity of Bph Dox. Steady-state kinetic assays using purified enzyme components demonstrated that KF707 Bph Dox had a kcatKm of 33.1×103 (M−1 s−1) for biphenyl. Evolved 1072 Bph Dox generated by the process of DNA shuffling (Suenaga, H. et al., J. Bacteriol., 184, 3682–3688 (2002)) exhibited enhanced degradation activity not only for biphenyl (kcatKm of 62.2×103 [M−1 s−1]) but also for benzene and toluene, compounds that are rarely attacked by KF707 Bph Dox. These results suggest that evolved 1072 Bph Dox acquires higher affinities and catalytic efficiencies for various substrates than the original KF707 enzyme.
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Biochemistry & Molecular Biology Communications
  • Jun-Ya WEI, An-Ming LI, Yin LI, Jing WANG, Xiao-Bin LIU, Liang-Shi LIU ...
    2006 Volume 70 Issue 4 Pages 1041-1045
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    RNase-related proteins (RRPs) are S- and S-like RNase homologs lacking the active site required for RNase activity. Here we describe the cloning and characterization of the rice (Oryza sativa) RRP gene (OsRRP). A single copy of OsRRP occurs in the rice genome. OsRRP contains three introns and an open reading frame encoding 252 amino acids, with the replacement of two histidines involved in the active site of RNase by lysine and tyrosine respectively. OsRRP is preferentially expressed in stems of wild-type rice and is significantly down-regulated in an increased tillering dwarf mutant ext37.
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  • Kazushige MATSUKAWA, Mika OGATA, Takashi HIKAGE, Hiroyuki MINAMI, Yosh ...
    2006 Volume 70 Issue 4 Pages 1046-1048
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    We describe a novel pharmacological activity of the gentian root, an ingredient of Chinese medicines. Root extract from Gentiana triflora triggered cell death of human Daudi cells in culture. In addition, daily administration of the extract to mice inhibited growth of implanted solid tumors. Extract treatment of cultured cells resulted in the appearance of shranken, fragmented, or condensed cell and nuclear morphologies, and in chromosomal DNA degradation. But, the extract-treated cells did not show DNA fragmentation, which exhibits a nucleosome ladder, suggesting that extract-triggered cell death is not mediated through a typical apoptotic pathway.
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Food & Nutrition Science Regular Papers
  • Satoshi HARAMIZU, Wataru MIZUNOYA, Yoriko MASUDA, Koichiro OHNUKI, Tat ...
    2006 Volume 70 Issue 4 Pages 774-781
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    We investigated the effect of capsiate, a nonpungent natural capsaicin analog, on the swimming capacity of mice in an adjustable-current water pool. Male BALB/c mice orally given capsiate (10 mg/kg) were able to keep swimming longer before exhaustion than the control mice. After 30 min of swimming, the residual glycogen in the gastrocnemius muscle was higher, the serum free fatty acid concentration tended to be higher, and the serum lactic acid concentration was significantly lower in the capsiate-administered mice. The value for the respiratory exchange ratio of the capsiate group was significantly lower during both resting and treadmill running. These physiological differences were abolished by administering the vanilloid receptor antagonist, capsazepin (0.17 mmol/kg, i.p.). The mice were not averse to the capsiate solution during a 4-h two-bottle choice test. These results suggest that the oral administration of capsiate enhanced fat oxidation and spared carbohydrate utilization, and consequently increased the endurance swimming capacity of the mice via stimulation of their vanilloid receptors. Practical application of capsiate is expected.
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  • Eriko YAHATA, Wakako MARUYAMA-FUNATSUKI, Zenta NISHIO, Yoshihiko YAMAM ...
    2006 Volume 70 Issue 4 Pages 788-797
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    The content of specific proteins such as high-molecular-weight glutenin subunits HMW-GS 5+10 and low-molecular-weight glutenin subunits LMW-GS KS2 in wheat mill streams of extra-strong Kachikei 33 wheat was quantified by SDS–PAGE and 2D-PAGE. The mill streams showed varied quantities of HMW-GS 5+10 (0.077 to 2.007 mg/g of mill stream), LMW-GS KS2 (0.018 to 0.586 mg/g of mill stream) and total protein (9.42% to 18.98%). The contents of these specific proteins in the mill streams were significantly correlated with the SDS sedimentation volume and the mixing properties, which are respective indices of specific loaf volume and dough strength. The contents of these specific glutenin proteins in the mill streams were therefore found to be significantly important for improving the dough quality suitable for bread and Chinese noodles. Accordingly, we present here the application of this information to the development of an effective method for producing mill streams with high quality and yield that are suitable for instant Chinese noodles.
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  • Byoung-Chul KIM, Youn-Chul RYU, Yoon-Je CHO, Min-Suk RHEE
    2006 Volume 70 Issue 4 Pages 808-814
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    This study examined the effect of dietary α-tocopheryl acetate on lipid and cholesterol oxidation in retail packed chicken meat during refrigerated storage. Male broiler chicks were randomly assigned to five pens containing 30 chicks each, which was subjected to one of five dietary treatments (0, 50, 100, 200, or 400 IU of α-tocopheryl acetate/kg diet). Five different levels of α-tocopherol were supplied to the chicks from 3 to 6 weeks. After 42 d of feeding all the broilers were slaughtered, and the carcasses were packed in polyethylene bags individually, bags similar to those used in the retail trade, and stored for 12 d at 4 °C. Growth performance and fatty acid composition were not affected by the dietary α-tocopherol levels. The α-tocopherol content in breast and thigh muscles increased as the level of dietary α-tocopherol increased. The supplementation with 200 or 400 IU of α-tocopherol was more effective in reducing the level of lipid oxidation (P<0.05) and total cholesterol oxidation products (P<0.05). Therefore, an increase in the dietary α-tocopherol level from 200 to 400 IU/kg feed causes major improvements in the oxidative stability of chicken meat during refrigerated storage.
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  • Tadashi SAKAI, Yukiko SHIMIZU, Satoshi KAWAHARA
    2006 Volume 70 Issue 4 Pages 815-820
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Pork was boiled at 100 °C for 5, 10 and 15 min and stored at 0 °C, and changes in the 4-hydroxynonenal (HNE), malonaldehyde (MA) and fatty acid (FA) contents were analyzed immediately and 3 days later. The HNE, MA and FA contents in all samples were not significantly different from each other. Pork samples containing none (control), 1% and 2% NaCl were boiled at 100 °C for 5 min and stored at 0 °C, and changes in the HNE, MA and FA contents and cooking yields were immediately analyzed and after 0, 1, 2 and 3 days. Cooking losses in the NaCl-containing samples were significantly lower than those of the control. The HNE contents in the control samples of boiled pork had significantly increased after 3 days of storage, while the contents in the NaCl-containing samples were significantly lower than those of the control after 1, 2 and 3 days of storage. The MA contents in all samples were not significantly different from each other. All FA contents analyzed had decreased in all samples after 3 days of storage. The decrease ratio of highly unsaturated fatty acids was lowest in the sample containing 2% NaCl.
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  • Naotoshi MATSUDOMI, Kazunari ITO, Youko YOSHIKA
    2006 Volume 70 Issue 4 Pages 836-842
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    The effects of phosvitin (PV) on insolubilization of egg white protein (EWP) and ovotransferrin (OT) were examined by measuring turbidity after heating at 80 °C in a pH range of 5 to 8. PV showed preventive ability against heat-insolubilization of EWP, especially heat-labile OT. The preventive ability of PV was reduced by adding NaCl to a PV-OT mixture on heating. Native PAGE and gel filtration analyses showed that PV prevented an insolubilization of heat-denatured OT through ionic interactions. The preventive effects of PV on insolubilization of EWP and OT resulted in the formation of a firm, transparent gel from EWP in coexistence with PV on heating. The addition of PV might make possible the preparation of liquid egg white without insoluble products even on heat-treatment at high temperatures.
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  • Hisa AOKI, Kumi KIMURA, Kiharu IGARASHI, Asako TAKENAKA
    2006 Volume 70 Issue 4 Pages 843-849
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Dietary soy protein isolate (SPI) reduces hepatic lipogenesis by suppressing gene expression of lipogenic enzymes, including acetyl-CoA carboxylase (ACC). In order to elucidate the mechanism of this regulation, the effect of dietary SPI on promoter (PI and PII) specific gene expression of ACC alpha was investigated. Rats were fed experimental diets containing SPI or casein as a nitrogen source. SPI feeding decreased the hepatic contents of total ACC mRNA as well as triglyceride (TG) content, but dietary SPI affected the amount of sterol-regulatory element binding protein (SREBP)-1 mRNA and protein very little. The amount of ACC mRNA transcribed from PII promoter containing SRE was not significantly affected by dietary protein, while a significant decrease in PI-generated ACC mRNA content was observed in rats fed the SPI diet. These data suggest that SPI feeding decreased the hepatic contents of ACC alpha mRNA mainly by regulating PI promoter via a nuclear factor(s) other than SREBP-1.
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  • Ji Young KIM, Yong Pil HWANG, Dong Hee KIM, Eun Hee HAN, Young Chul CH ...
    2006 Volume 70 Issue 4 Pages 858-864
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Previous studies have reported that the saponins isolated from the roots of Platycodon grandiflorum A. DC (Campanulaceae), Changkil saponins (CKS), inhibited cyclooxygenase-2 (COX-2) expression in cultured lipopolysaccharide-activated macrophages. The aim of this presented study was to confirm the anti-inflammatory effects of CKS by examining their effect on the inflammatory response induced by carrageenan in a rat by using an acute air pouch inflammation model. CKS significantly reduced the levels of the inflammatory process markers in the air pouch, such as the volume of exudates, the amount of protein and the number of leukocytes and neutrophils. The levels of TNF-α and prostaglandin E2 (PGE2) were also markedly lower in the air pouch of the CKS-treated animals than in the controls. An immunoblot analysis showed that CKS reduced the COX-2 expression level in the exudate cells. In addition, CKS significantly reduced the paw edema induced by carrageenan and also markedly reduced the level of PGE2 production in the inflamed paw. These results suggest that CKS had significant anti-inflammatory effects in vivo.
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  • Takahiro ISHIGURO, Tomotada ONO, Takahiro WADA, Chigen TSUKAMOTO, Yuhi ...
    2006 Volume 70 Issue 4 Pages 874-880
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    It is known that tofu quality tends to vary among soybeans even of the same variety. Cultivation environments can affect the contents of the soybeans. Twenty-seven soybean varieties were grown in a drained paddy field and an upland field, and then their protein and phytate contents were determined using the Fourier transfer infrared spectroscopy (FT-IR) method. The phytate contents of 12 varieties were higher in the drained paddy field than in the upland field. On the other hand, the environmental factor had little effect on the protein contents. In order to determine whether the difference in phytate content affected tofu texture, the hardness of the tofu made from phytate-added soymilk was measured. The tofu texture having more phytate became softer in the range of the common coagulant concentration. We concluded that the difference in the phytate content of the soybeans among the environmental conditions is a factor that causes fluctuation in tofu quality.
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  • Shuichi MASUDA, Yumeko TERASHIMA, Ayako SANO, Masaki OKADA, Yuya DEGUC ...
    2006 Volume 70 Issue 4 Pages 890-896
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    We determined the changes in the mutagenic and estrogenic activities of 17β-estradiol after a nitrite treatment. Nitrite-treated 17β-estradiol showed mutagenic activities toward Salmonella typhimurium strains TA 100 and TA 98. We confirmed that nitrite-treated 17β-estradiol generated radicals from the results of an analysis of electron spin resonance. By applying an instrumental analysis, we identified 2-nitro-17β-estradiol to have been formed in the reaction mixture. 2-Nitro-17β-estradiol did not exhibit mutagenic activities toward Salmonella typhimurium strains, suggesting that other mutagens might have been formed in the reaction mixture. The clastogenic properties of nitrite-treated 17β-estradiol and 2-nitro-17β-estradiol were analyzed by a micronucleus test with male ICR mice. Nitrite-treated 17β-estradiol and 2-nitro-17β-estradiol induced a significantly higher frequency of micronucleated reticulocytes in mice. The estrogenic activity of 2-nitro-17β-estradiol was found to be lower than that of 17β-estradiol. These data suggest that a daily oral intake of 17β-estradiol and nitrite might induce the formation of mutagenic compounds in our body.
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  • Yusuke OHSAKI, Hitoshi SHIRAKAWA, Kazuyuki HIWATASHI, Yuji FURUKAWA, T ...
    2006 Volume 70 Issue 4 Pages 926-932
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Vitamin K (K) is essential for blood coagulation and bone metabolism in mammals. K acts as a cofactor in the posttranslational synthesis of γ-carboxyglutamic acid from glutamic acid residues. In addition to the liver and bone, K is found in the brain, heart, kidney and gonadal tissue. However, the physiological role of K in these various organs is not yet fully understood. It is likely that K has functions other than its role as a cofactor of protein γ-glutamyl carboxylation. We used in this study the DNA microarray technique to identify the effect of K status on gene expression in the rat liver. The expression of genes involved in the acute inflammation response was enhanced in rats fed with a K-deficient diet relative to the control and K1-supplemented diet groups. Moreover, dietary supplementation with K1 suppressed the inflammation induced by lipopolysaccharide administration. These results indicate that orally administrated K1 suppressed inflammation in the rat.
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  • Yukiko YAMAMOTO, Eriko OUE
    2006 Volume 70 Issue 4 Pages 933-939
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    The effects of different levels of quercetin on the blood pressure were studied in 6-week-old male Sprague-Dawley rats. The rats were fed with a control diet or a high-fat high-sucrose (HFS) diet containing 0, 0.02, 0.07, 0.2, or 0.5% quercetin for 4 weeks. The systolic blood pressure and the lipid peroxides in the plasma were both higher in the rats fed with the HFS diet without quercetin than in the rats fed with the control diet. The nitric oxide synthase (NOS) activity in the vascular tissues and nitric oxide (NO) metabolites in the plasma and urine were both lower in these rats. A distinct depression of the increase in blood pressure was found in the rats fed with the HFS diets containing quercetin. Each level of quercetin examined was effective, the 0.5% level being much more effective than other levels. Dietary quercetin decreased lipid peroxidation in the plasma of the rats fed with the HFS diets. Quercetin also suppressed the decrease in NO metabolites in the plasma and urine, and the NOS activity in the vascular tissues of these rats. These results suggest that the increased NO availability caused by the elevated NOS activity, and the antioxidative activity in these rats fed with quercetin may be sources of the antihypertensive effect of quercetin.
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  • Ryosuke SHIMIZU, Hiroshi SHIMABAYASHI, Masamitsu MORIWAKI
    2006 Volume 70 Issue 4 Pages 940-948
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Myricitrin, a botanical flavonol glycoside, could be a useful ingredient of functional foods, cosmetics, and medicines because of its high anti-oxidative activity. However, due to its insolubility in water, it has a limited range of use. To improve this solubility, we glycosylated myricitrin by an enzymatic transglycosylate reaction. Myricitrin was galactosylated by β-galactosidase from Bacillus circulans using lactose as a sugar donor. The reaction product was 480 times more soluble than myricitrin. Four myricitrin galactosides were isolated from the reaction products by column chromatography, and their molecular structures were identified by using ESI-MS, 1H-NMR, 13C-NMR, 1H–1H COSY, 1H-13C HMQC and 1H-13C HMBC analysis. The solubility of these four myricitrin galactosides was more than 3.9×103 fold that of myricitrin, and each had similar anti-oxidative activity to that of myricitrin.
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  • Yoshiko KUROBAYASHI, Emi KOUNO, Akira FUJITA, Yasujiro MORIMITSU, Kiku ...
    2006 Volume 70 Issue 4 Pages 958-965
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    The raw and boiled odors of celery leaves and stalks were investigated. Among 12 compounds identified as potent odorants, 3-n-butylphthalide 1, sedanenolide 2, and trans- and cis-sedanolides 3, 4 were assessed to be most contributive to the overall odor of celery. These three phthalides, (3E,5Z)-1,3,5-undecatriene, myrcene, and (E)-2-nonenal were common to both raw and boiled materials. Two compounds, ((Z)-3-hexenal and (Z)-3-hexenol), were dominant in raw materials and four compounds, (2-methylbutanoic acid, sotolon, β-damascenone, and β-ionone), were dominant in boiled materials. Sensory evaluations were performed on natural celery odor and a series of reconstructed model aromas by assigning each intensity ratings for a set of seven odor qualities which aptly describe the odors of raw and boiled celery. According to the evaluation results, six common components contributed to the moderate odor of raw celery, two components dominant in raw materials enhanced the raw celery character, and four components dominant in boiled materials reduced the raw celery character and enhanced the boiled celery character. It was clarified that boiling-induced changes in celery odor were not affected by the amounts of phthalides, but by thermally generated compounds such as sotolon, β-damascenone, and β-ionone, which reduce the “green spicy” note.
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Food & Nutrition Science Notes
Microbiology & Fermentation Technology Regular Papers
  • Chi-Ming WU, Chuen-Fu LIN, Yi-Chih CHANG, Tung-Ching CHUNG
    2006 Volume 70 Issue 4 Pages 757-767
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    The Nisin-controlled gene expression (NICE) system, which was discovered in Lactococcus lactis, was adapted to Lactobacillus reuteri by ligating nisA promoter (PnisA) and nisRK DNA fragments into the Escherichia coli-Lb. reuteri shuttle vector pSTE32. This chimerical plasmid (pNICE) was capable of expressing the heterologous amylase gene (amyL) under nisin induction. Optimization of induction factors for this Lb. reuteri/pNICE system, including nisin concentration (viz. 50 ng/ml), growth phase of culture at which nisin be added (viz. at the early exponential phase), and the best time for analyzing the gene product after inoculation (viz. at the 3rd h), allowed the amylase product to be expressed in high amounts, constituting up to about 18% of the total intracellular protein. Furthermore, the signal peptide (SP) of amyL gene (SPamyL) from Bacillus licheniformis was ligated to the downstream of PnisA in pNICE, upgrading this vector to a NICE-secretion (NIES) level, which was then designated pNIES (Sec+, secretion positive). Characterization of pNIES using an amyL-SPΔ gene (amyL gene lacking its SP) as a reporter revealed the 3rd h after induction as the secretion peak of this system, at which the secretion efficiency and the amount of α-amylase being secreted into the culture supernatant were estimated to reach 77.6% and 27.75 mg/l. Expression and secretion of AmyL products by pNIES in Lb. reuteri was also confirmed by SDS–PAGE and immunoblotting analysis.
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  • Shinjiro TANOUE, Ken-ichi KAMEI, Hideya GODA, Akimitsu TANAKA, Tetsuo ...
    2006 Volume 70 Issue 4 Pages 782-787
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    The CCAAT-binding complex in Aspergillus species, known as the Hap complex, consists of at least three subunits, HapB, HapC, and HapE. Each Hap subunit contains an evolutionarily conserved core domain. In this study, a series of the truncated gene, which encodes the HapE subunit of Aspergillus oryzae, was constructed to survey the regions essential for the transcriptional enhancement of fungal genes. It was revealed that the non-conserved regions and the conserved region similar to the Hap4p recruiting domain of Saccharomyces cerevisiae were not necessary for Hap complex-mediated transcriptional enhancement.
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  • Satomi MIZUKAMI, Kiyoshi TAKEDA, Shinji AKADA, Takashi FUJITA
    2006 Volume 70 Issue 4 Pages 828-835
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    The population of filamentous acetate-utilizing methanogens in paddy field soils was 2.0×104 MPN/g dry soil in the submerged condition. They were able to form colonies in a deep agar medium, but not in a roll tube. Filamentous acetate-utilizing methanogens isolated from Kanagi, Japan (strain K-5) and Tsukuba, Japan (strain T-3) were divided into two types based on length of filaments. One type, strain K-5, formed a short chain which was dispersed easily by weak shaking. The other type, strain T-3, formed a long chain, which formed cotton-like flocs and was not dispersed by weak shaking. They had sheaths composed of a pair of adjacent membranes on the outside of the cell membranes. The 16S rRNA gene similarities of strain T-3 and K-5 to Methanosaeta concilii strain Opfikon were 100% and 99.5% respectively. Filamentous acetate-utilizing methanogens were also isolated from paddy field soils in various other regions of Japan. Our results suggest that Methanosaeta is universal in paddy soils and that it plays an important role in methane production from acetate.
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  • Emiko SHINAGAWA, Hirohide TOYAMA, Kazunobu MATSUSHITA, Pravate TUITEMW ...
    2006 Volume 70 Issue 4 Pages 850-857
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Membrane-bound NAD(P)-independent formaldehyde-oxidizing enzyme was purified to homogeneity from the membrane of Acetobacter sp. SKU 14 isolated in Thailand. The enzyme was solubilized from the membrane fraction of glycerol-grown cells with 1% Tween 20 at pH 2.85, and purified to homogeneity through the steps of column chromatographies on DEAE-Sephadex A-50 and Q-Sepharose in the presence of 0.1% Tween 20 and 0.1% Triton X-100. The enzyme purified together with a cytochrome c showed a single protein band on native-PAGE, and was dissociated into three different subunits upon SDS–PAGE with molecular masses of 78 kDa, 55 kDa, and 18 kDa. The purified enzyme was finally characterized as a quinoprotein alcohol dehydrogenase (QADH), and this is the first indication that QADH highly oxidizes formaldehyde. The substrate specificity of the enzyme was found to be broad toward aldehydes and alcohols, and alcohols, especially n-butanol, n-propanol, and ethanol, were oxidized more rapidly than formaldehyde.
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  • Akira IMAIZUMI, Chie KOSEKI, Kazuhiko MATSUI, Hiroyuki KOJIMA
    2006 Volume 70 Issue 4 Pages 949-957
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Using a DNA macroarray, we investigated the effects of rmf gene (encoding ribosome modulation factor) disruption on gene expression profiles in Escherichia coli. This strain showed a phosphate-starvation-like response in gene expression even under phosphate sufficient conditions; significant upregulation of the Pho regulon genes was observed. Further, the production of alkaline phosphatase, a product of the Pho regulon gene, phoA, increased in the rmf disruptant under a Pi sufficient condition. Furthermore, production of PhoC acid phosphatase/nucleoside pyrophosphate phosphotransferase derived from Morganella morganii also increased significantly in the rmf disruptant. We concluded that host modification by the rmf gene disruption has potential benefit in industrial enzyme production using Escherichia coli.
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Microbiology & Fermentation Technology Notes
  • Junko OHNISHI, Masato IKEDA
    2006 Volume 70 Issue 4 Pages 1017-1020
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Corynebacterium glutamicum is an industrially important organism that is most widely used for the production of various amino acids. A defined L-lysine-producing mutant was generated by introduction of the lysC mutation (T311I) into each of six representative C. glutamicum strains. The resulting six isogenic mutants were compared for L-lysine production under traditional 30 °C conditions and industrially more advantageous 40 °C conditions. It was found that there were significant differences in yield and productivity, especially at 40 °C. These results indicate the diversity among C. glutamicum strains in fermentative characters, as well as the importance of selecting a strain with industrially best performance.
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  • Takashi YOSHIMURA, Keisuke TSUGE, Toshihisa SUMI, Masahiro YOSHIKI, Yu ...
    2006 Volume 70 Issue 4 Pages 1026-1028
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    Marine microorganisms degrading porphyran (POR) were found on the surface of thalli of Porphyra yezoensis. Fifteen crude microorganism groups softened and liquefied the surface of agar-rich plate medium. Among these, 11 microorganism groups degraded porphyran that consisted of sulfated polysaccharide in Porphyra yezoensis. Following isolation, 7 POR-degradable microorganisms were isolated from the 11 POR-degradable microorganism groups.
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  • Ryo ENDO, Yoshiyuki OHTSUBO, Masataka TSUDA, Yuji NAGATA
    2006 Volume 70 Issue 4 Pages 1029-1032
    Published: 2006
    Released: April 23, 2006
    JOURNALS FREE ACCESS
    The growth of a γ-hexachlorocyclohexane (γ-HCH)-degrading bacterium Sphingobium japonicum (formerly Sphingomonas paucimobilis) UT26 in rich medium was inhibited by γ-HCH. This growth inhibition was not observed in a mutant that lacked the initial or second step enzymatic activity for γ-HCH degradation, suggesting that metabolites of γ-HCH are toxic to UT26. Two metabolites of γ-HCH, 2,5-dichlorophenol (2,5-DCP) and 2,5-dichlorohydroquinone (2,5-DCHQ), showed a direct toxic effect on UT26 and other sphingomonad strains. Because only 2,5-DCP accumulated during γ-HCH degradation, 2,5-DCP is thought to be a main compound for growth inhibition.
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