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951.
Hideki Okada Akira Yamamori Shuichi Onodera Norio Shiomi 《Carbohydrate research》2010,345(3):414-2637
Four oligosaccharides containing a fructopyranosyl residue have been found from fermented beverage of plant extract and isolated from the beverage using carbon-Celite column chromatography and preparative high performance liquid chromatography. Structure confirmation of the saccharides was provided by methylation analysis, MALDI-TOF-MS and NMR measurements. These saccharides were identified as oligosaccharides of fructopyranoside series; β-d-fructopyranosyl-(2→6)-d-fructofuranose (1), β-d-fructopyranosyl-(2→1)-d-fructopyranose (2), β-d-fructopyranosyl-(2→1)-β-d-fructofuranosyl-(2↔1)-α-d-glucopyranoside (3), and β-d-fructopyranosyl-(2→6)-α-d-glucopyranosyl-(1↔2)-β-d-fructofuranoside (4). Saccharides 3 and 4 among novel saccharides 1, 3, and 4 were named ‘pyrano-1-kestose (pyrano-isokestose)’ and ‘pyrano-neokestose’, respectively. 相似文献
952.
953.
954.
Satoshi Tomizawa Yuta Saito Manami Hyakutake Yoshiyuki Nakamura Hideki Abe Takeharu Tsuge 《Applied microbiology and biotechnology》2010,87(4):1427-1435
Polyhydroxyalkanoate (PHA) synthases catalyze chain transfer (CT) reaction after polymerization reaction of PHA by transferring
PHA chain from PHA synthase to a CT agent, resulting in covalent bonding of CT agent to PHA chain at the carboxyl end. Previous
studies have shown that poly(ethylene glycol) (PEG) is an effective exogenous CT agent. This study aimed to compare the effects
of PEG on CT reaction during poly[(R)-3-hydroxybutyrate] [P(3HB)] synthesis by using six PHA synthases in Escherichia coli JM109. The synthesized P(3HB) polymers were characterized in terms of molecular weight and end-group structure. Supplementation
of PEG to the culture medium reduced P(3HB) molecular weights by up to 96% due to PEG-induced CT reaction. The P(3HB) polymers
were subjected to 1H NMR analysis to confirm the formation of a covalent bond between PEG and P(3HB) chain at the carboxyl end. This study revealed
the reactivity of PHA synthases to PEG with respect to CT reaction in E. coli. 相似文献
955.
Sun Mee Hong Jun Yamashita Hitoshi Mitsunobu Keiro Uchino Isao Kobayashi Hideki Sezutsu Toshiki Tamura Hideki Nakajima Yoshitaka Miyagawa Jae Man Lee Hiroaki Mon Yoshihiko Miyata Yutaka Kawaguchi Takahiro Kusakabe 《Applied microbiology and biotechnology》2010,87(6):2147-2156
Baculovirus expression systems (BES) are widely used for recombinant protein production in lepidopteran cells or larvae. However, even in BES, the insolubility of recombinant proteins sometimes makes their expression difficult. In this study, to improve the solubility and yield of foreign proteins, we constructed transgenic silkworms using silkworm heat-shock proteins, Hsp70 and Hsp40, or Hsc70 and Hsp90 co-chaperone Hop. In these transgenic silkworms, the expression levels of the transgenes were under the control of a UAS·hsp mini-promoter driven by a Gal4NFkBp65 activator. When the transgenic silkworm with HSP70 and 40 (TGS-HSP70/40) was infected with BmNPV carrying mC3d and Gal4NFkBp65 under the control of baculovirus polyhedrin or p10 promoters, respectively, the soluble fraction of the His- or His·GST-tagged mC3d increased significantly. Similarly, the transgenic silkworm with HSC70 and HOP (TGS-HOP7) was effective for the expression of a steroid hormone receptor, USP2. In conclusion, the His-tagged baculovirus expression system featuring the chaperone effect TGS-HSP70/40 and TGS-HOP7 silkworms is effective for increasing the yields of soluble and functional foreign gene products. 相似文献
956.
Biotechnological production of enantiomeric pure lactic acid from renewable resources: recent achievements, perspectives, and limits 总被引:1,自引:0,他引:1
Kenji Okano Tsutomu Tanaka Chiaki Ogino Hideki Fukuda Akihiko Kondo 《Applied microbiology and biotechnology》2010,85(3):413-423
Lactic acid (LA) is an important and versatile chemical that can be produced from renewable resources such as biomass. LA
is used in the food, pharmaceutical, and polymers industries and is produced by microorganism fermentation; however, most
microorganisms cannot directly utilize biomass such as starchy materials and cellulose. Here, we summarize LA production using
several kinds of genetically modified microorganisms, such as LA bacteria, Escherichia coli, Corynebacterium glutamicum, and yeast. Using gene manipulation and metabolic engineering, the yield and optical purity of LA produced from biomass has
been significantly improved. In this review, the drawbacks as well as improvements of LA production by fermentation is discussed. 相似文献
957.
Noriko Sumi Tsuyoshi Nishioku Fuyuko Takata Junichi Matsumoto Takuya Watanabe Hideki Shuto Atsushi Yamauchi Shinya Dohgu Yasufumi Kataoka 《Cellular and molecular neurobiology》2010,30(2):247-253
The blood–brain barrier (BBB) is formed by brain capillary endothelial cells, astrocytes, pericytes, microglia, and neurons.
BBB disruption under pathological conditions such as neurodegenerative disease and inflammation is observed in parallel with
microglial activation. To test whether activation of microglia is linked to BBB dysfunction, we evaluated the effect of lipopolysaccharide
(LPS) on BBB functions in an in vitro co-culture system with rat brain microvascular endothelial cells (RBEC) and microglia.
When LPS was added for 6 h to the abluminal side of RBEC/microglia co-culture at a concentration showing no effects on the
RBEC monolayer, transendothelial electrical resistance was decreased and permeability to sodium-fluorescein was increased
in RBEC. Immunofluorescence staining for tight junction proteins demonstrated that zonula occludens-1-, claudin-5-, and occludin-like
immunoreactivities at the intercellular borders of RBEC were fragmented in the presence of LPS-activated microglia. These
functional changes induced by LPS-activated microglia were blocked by the nicotinamide adenine dinucleotide phosphate (NADPH)
oxidase inhibitor, diphenyleneiodonium chloride. The present findings suggest that LPS activates microglia to induce dysfunction
of the BBB by producing reactive oxygen species through NADPH oxidase. 相似文献
958.
Spatial variation of phosphorus fractions in bottom sediments and the potential contributions to eutrophication in shallow lakes 总被引:1,自引:0,他引:1
Yuichi Ishii Satoshi Harigae Shiho Tanimoto Tohru Yabe Tomohiko Yoshida Kazuo Taki Nobuyuki Komatsu Keiji Watanabe Masami Negishi Hideki Tatsumoto 《Limnology》2010,11(1):5-16
Spatial variation of phosphorus fractions in bottom sediment, pore water and overlying water in three shallow eutrophic lakes,
Nishiura, Kitaura and Sotonasakaura, Japan, and the contributions of the fractional P to mobilization of phosphorus from sediment
were examined in this study. The vertical distributions of dissolved inorganic phosphorus (DIP) concentrations in overlying
and pore water differed with lake and sampling site. In particular, DIP was high in pore water in the surface layer of the
sediment for the middle to downlake areas of Lake Kitaura. DIP release flux calculated from a gradient of the concentrations
at the sediment–water interface was high compared with other sites. The distribution of fractional P content in sediments
was highly variable. The citrate–dithionite–bicarbonate–non-reactive phosphorus (CDB–NRP) fraction, in particular, differed
greatly among the three lakes. According to correlation in the ratios between CDB–NRP and loss on ignition, sediments of these
lakes were classified in three clusters. The CDB–NRP fraction was suggested to play a role in DIP release from sediment. The
possibility of nitrate concentration playing a role in the control of DIP release was considered. 相似文献
959.
Ryosuke Yamada Naho Taniguchi Tsutomu Tanaka Chiaki Ogino Hideki Fukuda Akihiko Kondo 《Microbial cell factories》2010,9(1):32
Background
The filamentous fungus T. reesei effectively degrades cellulose and is known to produce various cellulolytic enzymes such as β-glucosidase, endoglucanase, and cellobiohydrolase. The expression levels of each cellulase are controlled simultaneously, and their ratios and synergetic effects are important for effective cellulose degradation. However, in recombinant Saccharomyces cerevisiae, it is difficult to simultaneously control many different enzymes. To construct engineered yeast with efficient cellulose degradation, we developed a simple method to optimize cellulase expression levels, named cocktail δ-integration. 相似文献960.
Naotoshi Mitsukawa Norihide Sugisaki Naokazu Miyamoto Toshimasa Yanai Hiroaki Kanehisa Tetsuo Fukunaga Yasuo Kawakami 《Journal of biomechanics》2010,43(8):1632-1634
This study aimed to investigate whether fatigue-induced changes in synergistic muscle forces match their tendon elongation. The medial gastrocnemius muscle (MG) was fatigued by repeated electrical stimulation (1 min×5 times: interval 30 s, intensity: 20–30% of maximal voluntary plantar flexion torque) applied at the muscle belly under a partial occlusion of blood vessels. Before and after the MG fatigue task, ramp isometric contractions were performed voluntarily, during which tendon elongations were determined by ultrasonography, along with recordings of the surface EMG activities of MG, the soleus (SOL) and the lateral gastrocnemius (LG) muscles. The tendon elongation of MG and SOL in post-fatigue ramp was similar, although evoked MG forces dropped nearly to zero. In addition, for a given torque output, the tendon elongation of SOL significantly decreased while that of LG did not, although the activation levels of both muscles had increased. Results suggest that the fatigue-induced changes in force of the triceps surae muscles do not match their tendon elongation. These results imply that the tendons of the triceps surae muscles are mechanically coupled even after selective fatigue of a single muscle. 相似文献