258 research outputs found

    ニンジン懸濁培養細胞の培養液に分泌される細胞外多糖成分

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    The extracellular polysaccharides have been fractionated from the culture medium of carrot(Daucus carota)cell culrures by precipitation with ethanol and by chromatography on DEAE-Sepharose CL-6B DEAE-Trisacryl M ion-exchange and Bio-Gel A-1.5m gel-permeation.The sugar composition and molecular mass of purified neutral and acidic polymers were determined. The neutral and acidic polymers were treated with purified endo-Β-glucanase from Trichoderma viride and pectic depolymerases,such as endo-pectate lyase from Erwinia carotovora Er. and endo-polygalacturonase from Kluyveromyces fragilis, respectively. The "hairly"(ramified)regions of acidic polymer were sequentially treated with purified α-L-arabinofuranosidase and β-galactosidase from carrot cell cultures, and were further hydrolyzed with 50mM trifluoroacetic for 1 hr at 100℃. From these results, the extracellular polysaccharides secreted from carrot cell cultures are charactarized.植物培養細胞は懸濁(液体)培養を行うことによって、細胞壁構成多糖成分と構造的に類似している多糖成分を、その培地中に分泌することが知られており、これまで数種の植物培養細胞について報告されている。そこで、これまで研究例のないニンジン培養細胞を使用して、その細胞外多糖成分について検討した。ニンジン懸濁培養細胞の対数増殖後期の培養濾液からエタノール分画によって多糖成分を集め、DEAE-Sepharose CL-6およびDEAE-Trisacry Mカラムクロマトグラフィーによって、数種の多糖画分に分画し、それら画分の構成糖組成を検討した。また、上記カラムに吸着しない中性多糖分画は、分子量52kDaと40kDaの2種の画分から成り、Trichoderma virideから分子量52kDaの画分はキシログルカンであると示唆された。一方、上記カラムに吸着する酸性多糖画分は、DEAE-Trisacryl M カラムクロマトグラフィーによって数種の画分に分画された。その中で、分子量80kDaを示す主要画分は、Erwinia carotovora Er.から精製したエンド‐ペクチン酸リアーゼ、Kluyveromyces fragilisから精製したエンド‐ポリガラクチュロナーゼ、ニンジン培養細胞から精製したα-L-アラビノフラノシダーゼやβ-ガラクトシダーゼなどによって分解されなかった。しかし、50mMのトリフルオロ酢酸による分解にて、4%に相当するガラクトースを含む生成物が遊離された。これらの結果から、この酸性多糖画分は、複雑な中性糖側鎖の結合したラムノガラクチュロナン領域(”Hairy”region)であることが示唆された

    Photo-degradation of imidazolium ionic liquids

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    金沢大学理工研究域自然システム学系Degradation of imidazolium ionic liquid, [bmim+][TFSA-] and iodide solution of [bmim+][TFSA-] by UV-laser irradiation has been studied through ground-state absorption and transient absorption spectroscopy. We found that excited state [bmim+]* undergoes degradation efficiently. © 2009 Elsevier Ltd. All rights reserved

    Topical Mevalonic Acid Stimulates De Novo Cholesterol Synthesis and Epidermal Permeability Barrier Homeostasis in Aged Mice11The authors did not submit a completed declaration of conflict of interest form as requested by the JID’s ‘‘Information for authors’’.

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    Extracellular lipids of the stratum corneum, which are composed of cholesterol, fatty acid, and ceramides, are essential for the epidermal permeability barrier function. With damage to the barrier, a decreased capacity for epidermal lipid biosynthesis in aged epidermis results in an impaired repair response. Mevalonic acid is an intermediate after the rate-limiting step in cholesterol biosynthesis, which is catalyzed by 3-hydroxy-3-methylglutaryl coenzyme A reductase. In the present study, we investigated the effect of topical mevalonic acid on the murine epidermal permeability barrier function, comparing it with that of cholesterol. Topical treatment with acetone caused linear increases in transepidermal water loss, in proportion to the number of treatments more rapidly in aged mice than in young mice. Administration of mevalonic acid on aged murine epidermis enhanced its resistance against damage and the recovery rate of barrier function from acute barrier disruption. In contrast, although cholesterol also had the same effect, it required a much higher amount than mevalonic acid. In young mice, neither mevalonic acid nor cholesterol had any effect on resistance against acetone damage nor the recovery rate from acetone damage. In the skin of mice topically administered with mevalonic acid, stimulation of cholesterol synthesis and 3-hydroxy-3-methylglutaryl coenzyme A reductase activity were both observed, whereas none was seen with stimulation by equimolar cholesterol. These data indicate that a topical application of mevalonic acid enhances barrier recovery in aged mice, which is accompanied by not only acceleration of cholesterol synthesis from mevalonic acid but also stimulation of the whole cholesterol biosynthesis

    Generation of a Mutant Mucor hiemalis Endoglycosidase That Acts on Core-fucosylated N-Glycans

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    Endo-β-N-acetylglucosaminidase M (Endo-M), an endoglycosidase from the fungus Mucor hiemalis, is a useful tool for chemoenzymatic synthesis of glycoconjugates, including glycoprotein-based therapeutics having a precisely defined glycoform, by virtue of its transglycosylation activity. Although Endo-M has been known to act on various N-glycans, it does not act on core-fucosylated N-glycans, which exist widely in mammalian glycoproteins, thus limiting its application. Therefore, we performed site-directed mutagenesis on Endo-M to isolate mutant enzymes that are able to act on mammalian-type core-α1,6-fucosylated glycans. Among the Endo-M mutant enzymes generated, those in which the tryptophan at position 251 was substituted with alanine or asparagine showed altered substrate specificities. Such mutant enzymes exhibited increased hydrolysis of a synthetic α1,6-fucosylated trimannosyl core structure, whereas their activity on the afucosylated form decreased. In addition, among the Trp-251 mutants, the W251N mutant was most efficient in hydrolyzing the core-fucosylated substrate. W251N mutants could act on the immunoglobulin G-derived core-fucosylated glycopeptides and human lactoferrin glycoproteins. This mutant was also capable of transferring the sialyl glycan from an activated substrate intermediate (sialyl glyco-oxazoline) onto an α1,6-fucosyl-N-acetylglucosaminyl biotin. Furthermore, the W251N mutant gained a glycosynthase-like activity when a N175Q substitution was introduced and it caused accumulation of the transglycosylation products. These findings not only give insights into the substrate recognition mechanism of glycoside hydrolase family 85 enzymes but also widen their scope of application in preparing homogeneous glycoforms of core-fucosylated glycoproteins for the production of potent glycoprotein-based therapeutics

    Recovery of Phosphate Rock Equivalents from Incineration Ash of Chicken Manure by Elution-Precipitation Treatment

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    In order to obtain calcium phosphates - a phosphate rock equivalent - from the incineration ash of chicken manure, which is obtained from power generation systems that use the manure for fuel, incineration ash was treated with an aqueous solution of nitric acid to elute phosphorus. By using 0.3 M of HNO3, most of the phosphorus could be eluted from 1.0 g of ash within 0.1 h. Compared with the composted chicken manure that was previously examined in our laboratory, the concentration of HNO3 was increased for this session of elution. Using the incineration ash of chicken manure made it possible to remove inorganic species at a lower boiling or sublimation temperature, and organic species by calcination in the power generation system. Compared with composted chicken manure, the concentrations of phosphorus contained in the incineration ash and the nitric acid extract were higher in the incineration ash. XRD analysis showed that the obtained nitric acid extract could be treated with aqueous NH3 to form a precipitation of poorly-crystallized calcium hydroxyapatite (Ca10(PO4)6(OH)2), which is one of main components in phosphate rock. In order to confirm the formation and purity of calcium phosphate species, the precipitation calcination was conducted at 1,078 K for 5 h. XRD revealed that the calcined solid was tricalcium phosphate, and no contamination was evident. These results reveal that a phosphate rock equivalent could be easily obtained from the incineration ash of chicken manure, which means that approximately 14% of the phosphate rock that is currently being imported into Japan could be replaced by this product

    Surgical removal of amyloid-laden lymph nodes: a possible therapeutic approach in a primary systemic AL amyloidosis patient with focal lymphadenopathy

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    We report a patient with primary systemic AL amyloidosis who suffered from remarkable bilateral cervical lymphadenopathy. Intensive chemotherapies, including two cycles of high-dose melphalan with autologous peripheral blood stem cell transplantation, were insufficiently effective for both the lymphadenopathy and amyloidogenic IgG lambda lambda-type M-protein in serum, but the patient showed complete haematological remission after extensive surgical removal of enlarged lymph nodes that had massive depositions of lambda lambda-type immunoglobulin light chain-derived amyloid. Lymphadenectomy may be a possible therapeutic approach with regard to both cosmetic and haematological aspects in primary systemic AL amyloidosis patients with focal lymphadenopathy.ArticleAMYLOID-JOURNAL OF PROTEIN FOLDING DISORDERS. 18(2):79-82 (2011)journal articl

    Micro Scanning Laser Range Sensor for Planetary Exploration

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    This paper proposes a new type of scanning laser range sensor for planetary exploration. The proposed sensor has advantages of small size, light weight, and low power consumption with the help of micro electrical mechanical systems technology. We are in the process of developing a miniature two dimensional optical sensor which is driven by a piezoelectric actuator. In this paper, we present the mechanisms and system concept of a micro scanning laser range sensor

    Reactions of excited-state benzophenone ketyl radical in a room-temperature ionic liquid

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    金沢大学理工研究域自然システム学系The photochemistry of the benzophenone ketyl radical in D1 excited state, BPH(D1), was studied by means of two-color dual-pulse laser flash photolysis (355 and 532 nm) in a room-temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (Bmim-TFSA), and in methanol. Upon excitation with the 532 nm pulse, BPH(D1) emitted strong fluorescence. The transient absorption and fluorescence spectra of BPH(D1) were measured with nanosecond and sub-nanosecond time resolution, respectively. The observed Stokes shift was 1700 cm-1 in Bmim-TFSA, and this shift was close to that in acetonitrile. The fluorescence lifetime of BPH(D1) was determined to be 5 ns in Bmim-TFSA, and again the value was close to that in acetonitrile. The rate constant of the reaction of BPH(D1) with CCl4 in Bmim-TFSA was determined to be (2.1 ± 0.4) × 109 M-1 s-1, which was 10 times the rate constant calculated on the basis of the bulk viscosity of Bmim-TFSA. The results are discussed in terms of the effective microscopic viscosity of the ionic liquid that was recently reported for the cage effect. © 2010 the Owner Societies

    N\'eel and Spin-Peierls ground states of two-dimensional SU(N) quantum antiferromagnets

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    The two-dimensional SU(N) quantum antiferromagnet, a generalization of the quantum Heisenberg model, is investigated by quantum Monte Carlo simulations. The ground state for N4N\le 4 is found to be of the N\'eel type with broken SU(N) symmetry, whereas it is of the Spin-Peierls type for N5N\ge 5 with broken lattice translational invariance. No intermediate spin-liquid phase was observed in contrast to previous numerical simulations on smaller lattices [Santoro et al., Phys. Rev. Lett. {\bf 83} 3065 (1999)].Comment: 4 pages, 4 figure
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