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91.
Kenichiro Kinouchi Atsuhiro Ichihara Motoaki Sano Ge-Hong Sun-Wada Yoh Wada Hiroki Ochi Toru Fukuda Kanako Bokuda Hideaki Kurosawa Naohiro Yoshida Shu Takeda Keiichi Fukuda Hiroshi Itoh 《PloS one》2013,8(11)
The ATPase 6 accessory protein 2 (ATP6AP2)/(pro)renin receptor (PRR) is essential for the biogenesis of active vacuolar H+-ATPase (V-ATPase). Genetic deletion of ATP6AP2/PRR causes V-ATPase dysfunction and compromises vesicular acidification. Here, we characterized the domains of ATP6AP2/PRR involved in active V-ATPase biogenesis. Three forms of ATP6AP2/PRR were found intracellularly: full-length protein and the N- and C-terminal fragments of furin cleavage products, with the N-terminal fragment secreted extracellularly. Genetic deletion of ATP6AP2/PRR did not affect the protein stability of V-ATPase subunits. The extracellular domain (ECD) and transmembrane domain (TM) of ATP6AP2/PRR were indispensable for the biogenesis of active V-ATPase. A deletion mutant of ATP6AP2/PRR, which lacks exon 4-encoded amino acids inside the ECD (Δ4M) and causes X-linked mental retardation Hedera type (MRXSH) and X-linked parkinsonism with spasticity (XPDS) in humans, was defective as a V-ATPase-associated protein. Prorenin had no effect on the biogenesis of active V-ATPase. The cleavage of ATP6AP2/PRR by furin seemed also dispensable for the biogenesis of active V-ATPase. We conclude that the N-terminal ECD of ATP6AP2/PRR, which is also involved in binding to prorenin or renin, is required for the biogenesis of active V-ATPase. The V-ATPase assembly occurs prior to its delivery to the trans-Golgi network and hence shedding of ATP6AP2/PRR would not affect the biogenesis of active V-ATPase. 相似文献
92.
93.
Kiyoshi Miwa Hiroshi Matsui Mahito Terabe Shigeru Nakamori Konosuke Sano Haruo Momose 《Bioscience, biotechnology, and biochemistry》2013,77(11):2901-2903
Seven filamentous (fil) mutants were isolated from B. subtilis, and the mutations were mapped by means of lysed-protoplast transformation. Five of the mutations were linked to aroD and the others to pyrD. rgn mutations, which lead to a decrease in autolysin(s) and the formation of filaments, were also linked to aroD, and the mapping order was rgn-dnaE-aroD. On comparison with other reported filamentous mutations (lyt-1, lyt-2 and lyt-152), fil-1, fil-3 to -6, rgn and the above lyt mutations were determined to be in the same locus. All of the seven fil strains lacked flagella and showed decreased aμtolysin activity. Among them, only mutants having arod- linked mutations showed low competency. Protease assay results indicated that rgn mutants produce a several times higher amount of the enzyme than the parent strain, and the initiation time for the production in rgn mutants was two hours earlier than in the parent strain. 相似文献
94.
Soichi Arai Michiko Yamashita Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(7):1253-1256
AK-toxin I, a host-specific toxin to Japanese pear (Pyrus serotina), was synthesized as its methyl ester from three precursor fragments: conjugated diene-carboxylic acid, chiral epoxyalcohol and β-methylphenylalanine. The epoxyalcohol fragment was derived from D-fructose, in which effective homologation of the hemiacetal carbon to alkyne by using dimethyl 1-diazo-2-oxopropylphosphonate was the key reaction. The diene-carboxylic acid fragment was prepared by repeated Wittig reactions, and was combined with the epoxyalcohol fragment by the Stille reaction. Esterification of the combined product with the stereochemically-pure β-methylphenylalanine fragment afforded the target compound. This method was used to prepare the methyl ester of tritium-labeled AK-toxin I with a specific radioactivity of 213 GBq/mmol. 相似文献
95.
Masao Fujimaki Soichi Arai Norimasa Kirigaya Yosito Sakurai 《Bioscience, biotechnology, and biochemistry》2013,77(9):855-863
Aliphatic carbonyl compounds in soybean were studied. Volatile carbonyl compounds in defatted soybean flour were identified as methanal, ethanal, n-hexanal, 2-propanone, 2- pentanone, 2-heptanone, 2-heptenal, and 2,4-decadienal, while those in raw soybean as ethanal, n-hexanal, and 2-propanone. Four kinds of non-volatile carbonyl compounds were found in defatted soybean, two of which seemed to be carbonyl ester and carbonylic acid. It is probable that the compounds in defatted soybean are mostly the secondary products derived from autoxidation of the residual fatty acids and esters in the defatting process and/or during the storage thereafter. n-Hexanal in raw soybean amounts to approximately 10 p.p.m., which is, owing to its extremely low flavoring threshold, likely to be one of the main components of the green bean flavor. 相似文献
96.
Soichi Arai Makoto Abe Michiko Yamashita Hiromichi Kato Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(4):552-559
An indole derivative having blue fluorescence was produced in cooked soybean digested at 37°C for 24 hr with an acid proteinase Molsin (optimum pH: 2.8) from Aspergillus saitoi or a usual acid proteinase pepsin (optimum pH: 1.6) from beef stomach. This indole derivative was identical with a condensation product from l-tryptophan and n-hexanal. Based on MS, NMR, IR and UV spectrometry, the condensation product was identified as l-pentyl-2, 3, 4, 9-tetrahydro-lH-pyrido [3, 4-b]-indole-3-carboxylic acid [trivial name: 1-pentyl-l, 2, 3, 4-tetrahydro-2-carboline carboxylic acid-(3)].Data were presented of the formation of the above indole derivative and of the resulting consumption of l-tryptophan and n-hexanal.The possible ocurrence of the formation of Harmala alkaloids, i.e. 2-carboline derivatives, through in vitro digestion of soybean with acid proteinases was discussed.A carbonyl-trapping ability of l-tryptophan was suggested. 相似文献
97.
Soichi Arai Masatoshi Noguchi Michiko Yamashita Hiromichi Kato Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(9):1338-1345
Soy proteins were incubated with a microbial acid protease (Molsin) under the following condition: substrate concentration, 1%; enzyme-substrate ratio (by weight), 1/100; pH, 2.8; and temperature, 40°C—flavor components and related impurities are removable from crude soy-protein concentrates by their incubation for 2 hr under the above condition. The acid-precipitated fraction of soy protein incubated for 2 hr with Molsin (i.e. 2 hr-proteolyzate) showed the following composition: 10% trichloroacetic acid (TCA) insoluble fraction, 47.52%; 10% TCA soluble peptide fraction, 52.02%; and free amino acid fraction, 0.46%. Gel filtration of the 2 hr-proteolyzate gave an elution pattern showing its molecular weight distribution.In the process of the incubation of the acid-precipitated protein, the 10% TCA insoluble fraction showed increase in amino nitrogen content, its solubility in a phosphate buffer increased to change at 6 hr, and a hydrophobic amino acid share in this fraction increased gradually.In vitro digestibility of the acid-precipitated fraction were improved and the lipoxygenase activity in this fraction decreased through the Molsin treatment.Ultracentrifugal analysis showed a decreasing tendency of the cold-insoluble fraction of soy protein during its incubation with Molsin. Optical rotatory dispersion and circular dichroism study elucidated conformational changes in this fraction during its incubation either with or without Molsin. 相似文献
98.
Michiko Yamashita Soichi Arai Shin-ya Tanimoto Masao Fujimaki 《Bioscience, biotechnology, and biochemistry》2013,77(4):953-954
An investigation was conducted on myosin and actin-activated heavy meromyosin (HMM) ATPase activities in normal porcine muscle stored for varying periods of time after death. Studies were also made on temperature dependent myosin ATPase, initial burst of ATPase and actin-activated HMM ATPase in normal and in pale, soft and exudative (PSE) porcine muscle. The maximum velocity of acto-HMM ATPase of normal muscle decreased considerably with postmortem time, while the apparent dissociation constant decreased slightly. The maximum velocity of acto-HMM ATPase of postmortem normal muscle was approximately two-times larger than that of the corresponding PSE muscle. However, almost no difference was found in the apparent dissociation constant. The size of the initial burst of phosphate-liberation of myosin prepared from normal muscle was approximately 1.2 mol/mol of myosin and from PSE muscle 0. It is assumed that the lack of contractility of PSE muscle was brought about by two basic myosin malfunctions: one, the irreversible binding of myosin to actin filament and the other, the functional damage of myosin ATPase, responsible for the formation of phosphorylated complex, even when dissociable. 相似文献
99.
Soichi Arai Hideki Suzuki Masao Fujimaki Yosito Sakurai 《Bioscience, biotechnology, and biochemistry》2013,77(4):364-369
Ethanol (1:1) extract of defatted soybean flour was fractionated systematically and the resulting phonolic acid fraction was investigated. This fraction had strong phenol-like flavor and contained at least seven phenolic acids including syringic, vanillic, ferulic, gentisic, salicylic, p-coumaric, and p-hydroxybenzoic acids. The main component among these was syringic acid, which was isolated as 3,5-dinitrobenzoate.In addition, two isomers of chlorogenic acids, presumably isochlorogenic and chlorogenic acids approximately in a ratio of 1 : 10, were found in this extract. These substances have sour, bitter and astringent flavors. 相似文献
100.
Yoshiyuki Sakano Mutsumi Sano Tsuneo Kobayashi 《Bioscience, biotechnology, and biochemistry》2013,77(12):3391-3398
Maltosyl-α-cyclodextrin (6-α-maltosylcyclomaltohexaose, M-CD) was prepared from maltose and α-cyclodextrin by the reverse action of Bacillus pullulanase, and the action of α-amylases on this dextrin was examined. Among α-amylases tested, Thermoactinomyces vulgaris α-amylase (TVA) and Taka-amylase A (TAA) were found to attack the M-CD. Their action pattern on M-CD was studied. These α-amylases cleaved, first the cyclodextrin ring of M-CD, and the branched octasaccharides formed were immediately degraded to form glucose, branched tetraose, or pentaose, though the action pattern was different for TVA and TAA. In addition, TAA also split M-CD into glucose and glucosyl-α-cyclodextrin. Fission products at various stages of the reaction were separated and analyzed by paper chromatography and high performance liquid chromatography, their structures were analyzed, and the degradation pattern of M-CD was found. 相似文献