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31.
Susumu Murata Hirokazu Matsui Seiya Chiba Tokuji Shimomura 《Bioscience, biotechnology, and biochemistry》2013,77(10):2131-2135
The substrate specificity of rice α-glucosidase II was studied. The enzyme was active especially on nigerose, phenyl-α-maltoside and maltooligosaccharides. The actions on isomaltose and phenyl-α-glucoside were weak, and on sucrose and methyl-α-glucoside, negligible. The α-glucans, such as soluble starch, amylopectin, β-limit dextrin, glycogen and amylose, were also hydrolyzed.The ratio of the maximum velocities for hydrolyses of maltose (G2), nigerose (N), kojibiose (K), isomaltose (I), phenyl-α-maltoside (?M) and soluble starch (SS) was estimated to be 100: 94.4: 14.2: 7.1: 89.5: 103.1 in this order, and that for hydrolyses of malto-triose (G3), -tetraose (G4), -pentaose (G5), -hexaose (G6), -heptaose (G7), -octaose (G8), and amyloses ( and ), 113: 113: 113: 106: 113: 100: 106: 106. The Km values for N, K, I, ?M and SS were 2.4 mm, 0.58 mm, 20 mm, 1.6 mm and 5.0 mg/ml, respectively; those for G2, G3, G4, G5, G6, G7, G8, and , 2.4 mm, 2.2 mm, 2.1 mm, 1.5 mm, 1.0 mm, 1.1 mm, 0.95 mm, 1.5 mm and 1.1 mm.Rice α-glucosidase II is considered an enzyme with a preferential activity on maltooligosaccharides. 相似文献
32.
Ken-ichi Kanaya Seiya Chiba Tokuji Shimomura 《Bioscience, biotechnology, and biochemistry》2013,77(10):1887-1893
A treatment of buckwheat α-glucosidase with N-acetylimidazole brought about the acétylation of 6.4 tyrosyl residues, 0.38 free sulfhydryl groups and about 50% of free amino groups, and the decrease in the hydrolytic activities toward maltooligosaccharides (G2~G8, G13) and soluble starch. The affinities for the substrate other than maltose were diminished by the modification and the extent of the reduction of the affinities was apparently dependent on the degree of polymerization of maltooligosaccharides, while the affinity for phenyl α- maltoside was increased. The treatment of the acetylated enzyme with hydroxylamine resulted in the complete restration of the affinities for all substrates tested. It seems that these facts were due to the acétylation of several tyrosyl residues located in or near certain subsites of the enzyme. About 25 % of the hydrolytic activity remained inert in spite of the deacetylation with hydroxylamine, which was assumed to be attributed to the partial modification of free sulfhydryl group localized closely near the catalytic site of the enzyme. 相似文献
33.
An α-glucosidase was purified from flint corn by precipitation with ammonium sulfate, chromatographies on CM-cellulose and Hydroxylapatite and gel-filtrations on Sephadex G-100. The purified enzyme was homogeneous in ultracentrifugal and disc electrophoretic analysis. The sedimentation coefficient was calculated to be 6.5 S. The molecular weight was estimated to be approximately 6.5×104 by gel-filtration technique.The optimal pH was found to be 3.6 for both maltose and soluble starch. The enzyme lost about 80% of the activity by incubation at 60°C for 10 min.The ratio of velocity of hydrolysis for maltose, phenyl-α-glucoside and soluble starch was estimated to be 100:14.3:6.1 in this order. The αglucosidase hydrolyzed soluble starch exo-wisely. 相似文献
34.
Hirokazu Matsui Seiya Chiba Tokuji Shimomura Nobuyuki Takahashi 《Bioscience, biotechnology, and biochemistry》2013,77(11):2239-2240
Hen lysozyme modified with histamine (HML) and Japanese quail lysozyme (JQL) were treated with immobilized metal ion affinity chromatography to analyze the states of their imidazole groups. When Ni(II) was used as the metal ion immobilized, JQL was strongly retained in a Ni(II)-chelating Sepharose column, while hen lysozyme and HML were hardly retained in the same column. All of these lysozymes have a histidine imidazole group at the 15th position, while JQL has an additional histidine imidazole group at the 103rd position and HML has an additional imidazole group covalently attached to Asp101. Thus, I concluded that the imidazole group at the 103rd position of JQL is exposed to the solvent and recognized by the metal ion, but that the imidazole group attached to Asp101 in HML is localized to a hydrophobic region and not recognized by the metal ion. 相似文献
35.
Takeshi Saeki Seiya Chiba Tokuji Shimomura 《Bioscience, biotechnology, and biochemistry》2013,77(2):551-552
A water-soluble and neutral polysaccharide was extracted from the current pseudobulbs of Oncidium “Gower Ramsey” during the early inflorescence stage (flower stalk less than 4 cm) by hot water, precipitated with ethanol, and purified with an anion exchanger. From the data of monosaccharide composition and linkage and anomeric configuration analyses, the polysaccharide was identified as a linear β-1→4 linked mannan. 相似文献
36.
Physiological anthropology presently covers a very broad range of human knowledge and engineering technologies. This study reviews scientific inconsistencies within a variety of areas: sitting posture; negative air ions; oxygen inhalation; alpha brain waves induced by music and ultrasound; 1/f fluctuations; the evaluation of feelings using surface electroencephalography; Kansei; universal design; and anti-stress issues. We found that the inconsistencies within these areas indicate the importance of integrative thinking and the need to maintain the perspective on the biological benefit to humanity. Analytical science divides human physiological functions into discrete details, although individuals comprise a unified collection of whole-body functions. Such disparate considerations contribute to the misunderstanding of physiological functions and the misevaluation of positive and negative values for humankind. Research related to human health will, in future, depend on the concept of maintaining physiological functions based on consistent science and on sustaining human health to maintain biological welfare in future generations. 相似文献
37.
Kazuki Kubo Hajime Monzen Kohei Shimomura Kenji Matsumoto Tomoharu Sato Mikoto Tamura Kiyoshi Nakamatsu Kentaro Ishii Ryu Kawamorita 《Reports of Practical Oncology and Radiotherapy》2019,24(6):600-605
AimTo evaluate the success of a patient-specific intensity modulated radiation therapy (IMRT) quality assurance (QA) practice for prostate cancer patients across multiple institutions using a questionnaire survey.BackgroundThe IMRT QA practice involves different methods of dose distribution verification and analysis at different institutions.Materials and MethodsTwo full-arc volumetric modulated arc therapy (VMAT) plan and 7 fixed-gantry IMRT plan with DMLC were used for patient specific QA across 22 institutions. The same computed tomography image and structure set were used for all plans. Each institution recalculated the dose distribution with fixed monitor units and without any modification. Single-point dose measurement with a cylindrical ionization chamber and dose distribution verification with a multi-detector or radiochromic film were performed, according to the QA process at each institution.ResultsTwenty-two institutions performed the patient-specific IMRT QA verifications. With a single-point dose measurement at the isocenter, the average difference between the calculated and measured doses was 0.5 ± 1.9%. For the comparison of dose distributions, 18 institutions used a two or three-dimensional array detector, while the others used Gafchromic film. In the γ test with dose difference/distance-to-agreement criteria of 3%?3 mm and 2%?2 mm with a 30% dose threshold, the median gamma pass rates were 99.3% (range: 41.7%–100.0%) and 96.4% (range: 29.4%–100.0%), respectively.ConclusionThis survey was an informative trial to understand the verification status of patient-specific IMRT QA measurements for prostate cancer. In most institutions, the point dose measurement and dose distribution differences met the desired criteria. 相似文献
38.
Nagashima Keiko Shimomura Tomotaka Tanaka Kazuhiro 《Landscape and Ecological Engineering》2019,15(2):155-166
Landscape and Ecological Engineering - Oak wilt disease and deer browsing have depleted the canopy and forest floor of secondary Quercus serrata and Quercus variabilis forests in Japan. Small-scale... 相似文献
39.
Genomewide association analysis in diverse inbred mice: power and population structure 总被引:4,自引:0,他引:4
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McClurg P Janes J Wu C Delano DL Walker JR Batalov S Takahashi JS Shimomura K Kohsaka A Bass J Wiltshire T Su AI 《Genetics》2007,176(1):675-683
The discovery of quantitative trait loci (QTL) in model organisms has relied heavily on the ability to perform controlled breeding to generate genotypic and phenotypic diversity. Recently, we and others have demonstrated the use of an existing set of diverse inbred mice (referred to here as the mouse diversity panel, MDP) as a QTL mapping population. The use of the MDP population has many advantages relative to traditional F(2) mapping populations, including increased phenotypic diversity, a higher recombination frequency, and the ability to collect genotype and phenotype data in community databases. However, these methods are complicated by population structure inherent in the MDP and the lack of an analytical framework to assess statistical power. To address these issues, we measured gene expression levels in hypothalamus across the MDP. We then mapped these phenotypes as quantitative traits with our association algorithm, resulting in a large set of expression QTL (eQTL). We utilized these eQTL, and specifically cis-eQTL, to develop a novel nonparametric method for association analysis in structured populations like the MDP. These eQTL data confirmed that the MDP is a suitable mapping population for QTL discovery and that eQTL results can serve as a gold standard for relative measures of statistical power. 相似文献
40.