557 research outputs found

    Cloning and Expression of a Perilla frutescens Cytochrome P450 Enzyme Catalyzing the Hydroxylation of Phenylpropenes

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    Phenylpropanoid volatile components in plants are useful and valuable not only as flavorings, but also as medicines and food supplements. The pharmacological actions and toxicities of these compounds have been well studied but their synthetic pathways are generally unclear. In this study, we mined expressed sequence tag libraries of pure strains of perilla maintained for over 30 years for their oil type and conducted gas chromatography-mass spectrometry analyses of the perilla oils to confirm the presence of monohydrates speculated to be intermediates of the phenylpropene synthetics pathways. These putative monohydrate intermediates and their regioisomers were synthesized to identify the reaction products of assays of heterologously expressed enzymes. An enzyme involved in the synthesis of a phenylpropanoid volatile component was identified in perilla. Expression of this enzyme in Saccharomyces cerevisiae showed that it is a member of the cytochrome P450 family and catalyzes the introduction of a hydroxy group onto myristicin to form an intermediate of dillapiole. The enzyme had high sequence similarity to a CYP71D family enzyme, high regiospecificity, and low substrate specificity. This study may aid the elucidation of generally unexploited biosynthetic pathways of phenylpropanoid volatile components

    A1F-B, a novel CCAAT-binding transcription activator that interacts with the aldolase B promoter

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    AbstractWe describe here a 70 kDa transcription factor A1F-B, which preferentially binds to an element encompassing a CCAAT motif on the rat aldolase B promoter. Comparison of binding specificities, relative molecular masses, and subunit compositions with those of other known CCAAT-binding factors indicated that A1F-B is a novel member of CCAAT-binding factors

    Neutron Diffraction Study of the Intermetallic Compound FeSi

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    A powder neutron diffraction study has been made on the intermetallic compound, FeSi. From magnetic measurements this substance has been believed to be antiferromagnetic below 170℃. Neutron diffraction measurements at room temperature and at liquid nitrogen temperature, however, show no coherent antiferromagnetic intensity, thus ruling out any long range magnetic order. Some results of magnetic measurements and discussion are presented

    チョウキ トウセキ カンジャ ニオケル エイヨウ カンリ ト ショクセイカツ ノ モンダイテン : リン ノ ジュウヨウセイ ニツイテ

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    Hyperphosphatemia continues to affect a large portion of the dialysis population and is associated with increased patient mortality, secondary hyperparathyroidism, renal osteodystrophy (ROD), and therapeutic failure of calcitriol. Elevated serum phosphorus is implicated in the pathogenesis of ROD through its effects on calcium and calcitriol levels, PTH production, and parathyroid cell proliferation. The exact role of phosphorus in ROD is not completely defined, however, and clinical management of ROD is complicated by interactions between phosphorus, calcium, PTH, and calcitriol. Despite these challenges, strategies for managing ROD-including early control of serum phosphorus and PTH by low phosphate diet, establishment of markers for optimal parathyroid and bone health, and availability of new therapeutic tools-can help prevent complications and improve patient outcomes

    Improved Neural Processing Efficiency in a Chronic Aphasia Patient Following Melodic Intonation Therapy: A Neuropsychological and Functional MRI Study

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    Melodic intonation therapy (MIT) is a treatment program for the rehabilitation of aphasic patients with speech production disorders. We report a case of severe chronic non-fluent aphasia unresponsive to several years of conventional therapy that showed a marked improvement following intensive nine-day training on the Japanese version of MIT (MIT-J). The purposes of this study were to verify the efficacy of MIT-J by functional assessment and examine associated changes in neural processing by functional magnetic resonance imaging. MIT improved language output and auditory comprehension, and decreased the response time for picture naming. Following MIT-J, an area of the right hemisphere was less activated on correct naming trials than compared to before training but similarly activated on incorrect trials. These results suggest that the aphasic symptoms of our patient were improved by increased neural processing efficiency and a concomitant decrease in cognitive load

    Hydrogen sulfide activates TRPA1 and releases 5-HT from epithelioid cells of the chicken thoracic aorta

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    Epithelioid cells in the chicken thoracic aorta are chemoreceptor cells that release 5-HT in response to hypoxia. It is likely that these cells play a role in chemoreception similar to that of glomus cells in the carotid bodies of mammals. Recently, H2S was reported to be a key mediator of carotid glomus cell responses to hypoxia. The aim of the present study was to reveal the mechanism of action of H2S on 5-HT outflow from chemoreceptor cells in the chicken thoracic aorta. The 5-HT outflow induced by NaHS, an H2S donor, and Na2S3, a polysulfide, was measured by using a HPLC equipped with an electrochemical detector. NaHS (0.3-3 mM) caused a concentration-dependent increase in 5-HT outflow, which was significantly inhibited by the removal of extracellular Ca2+. outflow induced by NaHS (0.3 mM) was also significantly inhibited by voltage-dependent L- and N-type Ca2+ channel blockers and a selective TRPA1 channel blocker. Cinnamaldehyde, a TRPA1 agonist, mimicked the secretory response to H2S. 5-HT outflow induced by Na2S3 (10 M) was also inhibited by the TRPA1 channel blocker. Furthermore, the expression of TRPA1 was localized to 5-HT-containing chemoreceptor cells in the aortic wall. These findings suggest that the activation of TRPA1 and voltage-dependent Ca2+ channels is involved in H2S-evoked 5-HT release from chemoreceptor cells in the chicken aorta. (C) 2016 Elsevier Inc. All rights reserved

    \u3ci\u3eIn vitro\u3c/i\u3e assembly of apophytochrome and apophytochrome deletion mutants expressed in yeast with phycocyanobilin

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    Recombinant pea type I phytochrome apoprotein expressed in yeast is shown to assemble in vitro with phycocyanobilin to produce a photoreversible phytochromelike adduct. As an initial investigation of the amino acid sequence requirements for chromophore incorporation, three phyA gene product deletion mutants were produced in yeast. Truncation of the N-terminal tail to residue 46 demonstrates that this region is not critical to bilin attachment, but a deletion mutant lacking 222 amino acids from the N terminus failed to yield holophytochrome in vitro, under the same conditions. A mutant comprising a deletion of the C terminus to residue 548 showed bilin incorporation and red/far-red photoreversibility, indicating that bilin-apophytochrome assembly still occurred even when the entire C-terminal domain was truncated
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