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991.
992.
Development and evaluation of an automated workstation for single nucleotide polymorphism discrimination using bacterial magnetic particles 总被引:4,自引:0,他引:4
Tanaka T Maruyama K Yoda K Nemoto E Udagawa Y Nakayama H Takeyama H Matsunaga T 《Biosensors & bioelectronics》2003,19(4):325-330
We designed an automated workstation for magnetic particle-based single nucleotide polymorphism (SNP) discrimination of ALDH genotypes. Bacterial magnetic particles (BMPs) extracted from Magnetospirillum magneticum AMB-1 were used as DNA carriers. The principle for SNP discrimination in this study was based on fluorescence resonance energy transfer (FRET) between FITC (donor) and POPO-3 (acceptor) bound to double-stranded DNA. The workstation is equipped with a 96-way automated pipetter which collects and dispenses fluids as it moves in x- and z-directions. The platform contains a disposable tip rack station, a reagent vessel serving as a stock for POPO-3 and FITC-labeled probes and a reaction station for a 96-well microtiter plate. BMPs were collected by attaching a neodymium iron boron sintered (Nd-Fe-B) magnet on the bottom of the microtiter plate. This system permits the simultaneous heating and magnetic separation of 96 samples per assay. The genotypes ALDH2*1 and ALDH2*2 were discriminated by calculating the relative fluorescence intensities on BMPs. 相似文献
993.
A novel methylthio metabolite of s-triazolo[3,4-a]phthalazine, a lead compound for the development of antianxiety drugs, in rats 总被引:1,自引:0,他引:1
When s-triazolo[3,4-a]phthalazine (Tri-P) was orally administered in rats, a more lipophilic metabolite M-1 than the parent compound was isolated from the urine. The metabolite M-1 was identified as 7-methylthio Tri-P by means of high resolution MS and two-dimensional NMR spectrometry. Furthermore, the 7-methylthio conjugate was generated from the parent compound Tri-P in isolated rat hepatocytes. Although the contribution of the intestinal microflora to the formation of methylthio metabolite has been pointed out so far, the limited data in this study lead us to conclude that the liver plays a role in all metabolic reactions of Tri-P to its 7-methylthio conjugate in rats. 相似文献
994.
Watanabe Tsuneo; Kondo Noriaki; Fujii Tadashi; Noguchi Teruhisa 《Plant & cell physiology》1977,18(2):387-392
A method was established to purify acrylate decarboxylase fromPorphyra tenera by affinity chromatography using a proteinaceousinhibitor of ethylene evolution in marine algae, isolated fromP. tenera as a ligand. The proteinaceous inhibitor was covalentlycoupled to porous glass via four different spacer arms. Theporous glass-aminopropyltriethoxysilane-succinatephenylendiamine-succinate-inhibitorappeared to be the best derivative for retaining acrylate decarboxylaseextracted from P. tenera. Acrylate decarboxylase was extracted from 10 kg of P. teneraand semi-purified by ammonium sulfate. preparation and gel filtrationon Sephadex G-100. The active fraction was applied to an affinitycolumn. Acrylate decarboxylase was eluted in the starting buffercontaining 0.2 M NaCl. Ethylene formation from acrylate wasdetected in the presence of this enzyme extract, but not inthe case of the boiled enzyme extract. Acrylate decarboxylasewas inhibited by the inhibitor isolated from P. tenera. Thesefacts indicate that the formation of ethylene in marine algaefrom acrylate proceeds enzymatically.
2 Present address: Division of Environmental Biology, NationalInstitute for Environmental Studies, Yatabe, Ibaraki 300-21,Japan. (Received July 13, 1976; ) 相似文献
995.
Takeshi Murakawa Akio Hamaguchi Shota Nakanishi Misumi Kataoka Tadashi Nakai Yoshiaki Kawano Hiroshi Yamaguchi Hideyuki Hayashi Katsuyuki Tanizawa Toshihide Okajima 《The Journal of biological chemistry》2015,290(38):23094-23109
The catalytic reaction of copper amine oxidase proceeds through a ping-pong mechanism comprising two half-reactions. In the initial half-reaction, the substrate amine reduces the Tyr-derived cofactor, topa quinone (TPQ), to an aminoresorcinol form (TPQamr) that is in equilibrium with a semiquinone radical (TPQsq) via an intramolecular electron transfer to the active-site copper. We have analyzed this reductive half-reaction in crystals of the copper amine oxidase from Arthrobacter globiformis. Anerobic soaking of the crystals with an amine substrate shifted the equilibrium toward TPQsq in an “on-copper” conformation, in which the 4-OH group ligated axially to the copper center, which was probably reduced to Cu(I). When the crystals were soaked with substrate in the presence of halide ions, which act as uncompetitive and noncompetitive inhibitors with respect to the amine substrate and dioxygen, respectively, the equilibrium in the crystals shifted toward the “off-copper” conformation of TPQamr. The halide ion was bound to the axial position of the copper center, thereby preventing TPQamr from adopting the on-copper conformation. Furthermore, transient kinetic analyses in the presence of viscogen (glycerol) revealed that only the rate constant in the step of TPQamr/TPQsq interconversion is markedly affected by the viscogen, which probably perturbs the conformational change. These findings unequivocally demonstrate that TPQ undergoes large conformational changes during the reductive half-reaction. 相似文献
996.
Kobayashi Mina Okajima Isa Narisawa Hajime Kikuchi Takashi Matsui Kentaro Inada Ken Ishigooka Jun Inoue Yuichi 《Sleep and biological rhythms》2018,16(3):263-271
Sleep and Biological Rhythms - For prevention and early detection of dependence on hypnotics such as benzodiazepines (BZDs) or its agonists, a withdrawal symptom scale specialized for this kind of... 相似文献
997.
Rieko Oyama Mami Takahashi Fusako Kito Marimu Sakumoto Kumiko Shiozawa Zhiwei Qiao Akihiko Yoshida Makoto Endo Akira Kawai Tadashi Kondo 《In vitro cellular & developmental biology. Animal》2018,54(6):458-467
Primary leiomyosarcoma (LMS) of bone is a rare and aggressive mesenchymal malignancy that differentiates toward smooth muscle. Complete resection is the only curable treatment, and novel therapeutic approaches for primary LMS of bone have long been desired. Patient-derived xenografts (PDXs) and cell lines are invaluable tools for preclinical studies. Here, we established PDXs from a patient with primary LMS of bone and a cell line from an established PDX. Bone primary LMS tissue was subcutaneously implanted into highly immune-deficient mice. After two passages, a piece of the tumor was subjected to tissue culturing, and a morphological evaluation and proteomic analysis were performed on the PDX and the established cell line. Moreover, the responses of the established cell line to anti-cancer drugs were examined. Microscopic observations revealed that the PDX tumors retained their original histology. The cell line was established from the third-generation PDX and named NCC-LMS1-X3-C1. The cells were maintained for over 18 mo and 40 passages. The cells exhibited a spindle shape and aggressive growth. Mass spectrometric protein identification revealed that the original tumor tissue, PDX tumor tissue, and NCC-LMS1-X3-C1 cells had similar but distinct protein expression profiles. We previously established the cell line, NCC-LMS1-C1, from the tumor tissue of same patient. We found that the response to drug treatments was different between NCC-LMS1-X3-C1 and NCC-LMS1-C1, suggesting the heterogeneous traits of tumor cells in the identical tumor tissue. This set of PDXs and stable cell line will be a useful resource for bone LMS research. 相似文献
998.
Igawa Tatsuhiro Kishikawa Shuhei Abe Yoshito Yamashita Tomohiro Nagai Saki Shiroishi Mitsunori Shinozaki Chinatsu Tanaka Hiroyuki Tozaki-Saitoh Hidetoshi Tsuda Makoto Inoue Kazuhide Ueda Tadashi 《Purinergic signalling》2019,15(1):27-35
Purinergic Signalling - P2X purinergic receptors are ATP-driven ionic channels expressed as trimers and showing various functions. A subtype, the P2X4 receptor present on microglial cells is highly... 相似文献
999.
Kunihiko Gekko Mariko Araga Tadashi Kamiyama Eiji Ohmae Kazuyuki Akasaka 《Biophysical chemistry》2009,144(1-2):67-71
There are some theoretical arguments related to interpreting the adiabatic compressibility (βs) of a protein determined from the sound velocity and the difference between βs and isothermal compressibility (βT). To address these problems experimentally, we constructed a high-pressure oscillating densitometer and used it to measure the apparent specific volume of bovine serum albumin as a function of pressure (0.1–78 MPa) and temperature (5–35 °C). The βT determined from plots of the apparent specific volume vs. pressure was slightly larger than βs at all temperatures examined, with the difference between the two compressibilities increasing as the temperature was decreased. Only at room temperature did the observed βT agree with those estimated from βs using the heat capacity and the thermal expansibility of the protein, suggesting that there are significant as-yet-unknown mechanisms that affect protein compressibility. 相似文献
1000.
d-Alanine production from dl-alanine by Candida maltosa with asymmetric degrading activity 总被引:3,自引:0,他引:3
Isao Umemura Koji Yanagiya Saburo Komatsubara Tadashi Sato Tetsuya Tosa 《Applied microbiology and biotechnology》1992,36(6):722-726
Summary To develop a practical process for d-alanine production from dl-alanine, we screened 107 yeasts for their asymmetric degrading activity against dl-alanine. Candida maltosa JCM1504 degraded the l-isomer ten times more rapidly than the d-isomer. The cells of this strain were used as a biocatalyst for eliminating the l-isomer. However, when the degradation reaction was conducted in the presence of a high concentration of dl-alanine, the pH of the reaction mixture was rapidly increased by the liberation of ammonia from l-alanine, and consequently the reaction stopped. This hindrance was overcome by controlling the pH value at 6.0 with H2SO4 during the reaction. Additionally, we found that the maximum rate of l-isomer degradation was obtained at 30° C and pH 6.0 under conditions of high aeration (1.0 vvm) and agitation (1200 rpm). Under the optimal conditions, the l-isomer of 200 g dl-alanine/l was completely degraded within 40 h and 90 g d-alanine/l remained in the reaction mixture. d-Alanine was easily isolated from the reaction mixture. The chemical and optical purity of the d-isomer product so obtained was 99.0% and 99.9% enantiomeric excess, respectively.Offprint requests to: I. Umemura 相似文献