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101.
Effects of thyroid hormones and their metabolites such as L-T1, L-T2, L-T3 and L-T4 on human erythrocyte acetylcholine esterase were studied. The activity of the enzyme of intact erythrocytes was not affected by these hormones, though studied under various conditions. The physiological significance of the binding of these hormones to erythrocyte membranes remains unclear. Our results indicate that the acetylcholine esterase is not a suitable enzyme for cytochemical bioassay for thyroid hormones. 相似文献
102.
103.
Kenji Doi Akemi Doi Takeshi Ozaki Toshio Fukui 《Bioscience, biotechnology, and biochemistry》2013,77(7):1629-1633
The action pattern of lytic β-1,3 glucanase (glucanase I) from Arthrobacter which liberates predominantly laminaripentaose from various β-glucans has been studied. The enzyme was not active on short linear laminaridextrins, but was active on an enzymatically synthesized, linear β-1,3 oligoglucan preparation. Any intactness of the glucose residues of the chain ends of a substrate did not seem to be necessary for the action of the enzyme. The results of determination of laminaripentaose during a relatively early phase of the reaction suggested that about half of the reducing power liberated in the medium might be explained by the formation of the sugar. It seems that the formation of laminaripentaose relates to the initial attack of glucanase 1 on β-1,3 glucan chains. 相似文献
104.
Motoaki Sato Prem Kumar Sinha Jesus Torres-Bacete Akemi Matsuno-Yagi Takao Yagi 《The Journal of biological chemistry》2013,288(34):24705-24716
The proton-translocating NADH-quinone oxidoreductase (complex I/NDH-1) contains a peripheral and a membrane domain. Three antiporter-like subunits in the membrane domain, NuoL, NuoM, and NuoN (ND5, ND4 and ND2, respectively), are structurally similar. We analyzed the role of NuoN in Escherichia coli NDH-1. The lysine residue at position 395 in NuoN (NLys395) is conserved in NuoL (LLys399) but is replaced by glutamic acid (MGlu407) in NuoM. Our mutation study on NLys395 suggests that this residue participates in the proton translocation. Furthermore, we found that MGlu407 is also essential and most likely interacts with conserved LArg175. Glutamic acids, NGlu133, MGlu144, and LGlu144, are corresponding residues. Unlike mutants of MGlu144 and LGlu144, mutation of NGlu133 scarcely affected the energy-transducing activities. However, a double mutant of NGlu133 and nearby KGlu72 showed significant inhibition of these activities. This suggests that NGlu133 bears a functional role similar to LGlu144 and MGlu144 but its mutation can be partially compensated by the nearby carboxyl residue. Conserved prolines located at loops of discontinuous transmembrane helices of NuoL, NuoM, and NuoN were shown to play a similar role in the energy-transducing activity. It seems likely that NuoL, NuoM, and NuoN pump protons by a similar mechanism. Our data also revealed that NLys158 is one of the key interaction points with helix HL in NuoL. A truncation study indicated that the C-terminal amphipathic segments of NTM14 interacts with the Mβ sheet located on the opposite side of helix HL. Taken together, the mechanism of H+ translocation in NDH-1 is discussed. 相似文献
105.
Takashi Sugita Koichi Makimura Akemi Nishikawa Katsuhisa Uchida Hideyo Yamaguchi Takako Shinoda 《Microbiology and immunology》1997,41(7):571-573
We determined the partial sequences of large subunit rDNA of a new yeast species, Trichosporon domesticum, which was isolated from the house of a summer-type hypersensitivity pneumonitis patient. Phylogenetically, T. domesticum was positioned in the taxonomic group containing T. montevideense and T. brassicae, which indicated an identical serotype. A phylogenetic relationship among all species of the genus Trichosporon which belong to the basidiomycetous yeast is clarified. 相似文献
106.
107.
Mukohata Yasuo; Yagi Takao; Higashida Mitsuhiro; Matsuno Akemi; Sugiyama Yasuo 《Plant & cell physiology》1974,15(4):619-628
Spinach chloroplasts were isolated and stored in a medium containing0.5 M choline chloride. The properties of these chloroplastswere compared with those of chloroplasts prepared in an ordinarysucrose medium. In marked contrast to sucrose-prepared chloroplasts, choline-preparedchloroplasts did not show "conventional uncoupling" (stimulationof ferricyanide reduction paralleling the inactivation of phosphorylation)after transient warming in the temperature range between 20?and 55?C. The thermal stability of the oxygen evolving system, the vulnerabilityof the lipophilic structure in the thylakoids to alcohol duringthe warming treatment, and the effects of amine on photophosphorylationwere similar in both chloroplast preparations. After the warming treatment, the degree of swelling in chloroplastswas larger and the intermediate electron transport systme (fromreduced 2,6-dichlorophenolindophenol to methyl viologen) wasmore stable against uncoupling, in choline-prepared chloroplaststhan in sucrose-prepared ones. The presence and absence of "conventional uncoupling" in twochloroplast preparations were ascribed to differences in thermalstability. In choline-prepared chloroplasts the uncoupling temperatureof the electron transport system was higher than the inactivationtemperature of the oxygen evolving system, but it was lowerin the sucrose-prepared ones. (Received February 13, 1974; ) 相似文献
108.
Yasuo Mukohata Takao Yagi Mitsuhiro Higashida Akemi Matsuno 《Journal of bioenergetics and biomembranes》1973,4(5):479-490
Spinach chloroplasts pre-incubated at various temperatures, changed their photosynthetic activities (measured at 15°C) as the incubation temperature was raised; these activities showed characteristic activitytemperature profiles as follows:
- The profiles were shifted to lower temperatures if various aliphatic compounds were present in the incubation mixture.
- In general, the extent of the shift was proportional to the product of the concentration and the partition coefficient of the compound, i.e. to the concentration of the compound partitioned in the lipophilic chloroplast phase.
109.
Bai Songling Tuan Pham Anh Tatsuki Miho Yaegaki Hideaki Ohmiya Akemi Yamamizo Chihiro Moriguchi Takaya 《Plant Molecular Biology Reporter》2016,34(1):257-264
Plant Molecular Biology Reporter - Transgenic approach is an excellent way for the clarification of gene function, but it is generally difficult to create transgenic plants for most of the fruit... 相似文献
110.
Sana Ben Othman Nakako Katsuno Akemi Kitayama Makoto Fujimura Kohji Kitaguchi 《Free radical research》2016,50(9):949-958
Oxidative stress is involved in the development of aging-related diseases, such as neurodegenerative diseases. Dietary antioxidants that can protect neuronal cells from oxidative damage play an important role in preventing such diseases. Previously, we reported that water-soluble fractions purified from defatted sesame seed flour exhibit good antioxidant activity in vitro. In the present study, we investigated the protective effects of white and gold sesame seed water-soluble fractions (WS-wsf and GS-wsf, respectively) against 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH) and hydrogen peroxide (H2O2) induced oxidative stress in human neuroblast SH-SY5Y cells. Pretreatment with WS-wsf and GS-wsf did not protect cells against AAPH-induced cytotoxicity, while simultaneous co-treatment with AAPH significantly improved cell viability and inhibited membrane lipid peroxidation. These results suggest that WS-wsf and GS-wsf protect cells from AAPH-induced extracellular oxidative damage via direct scavenging of peroxyl radicals. When oxidative stress was induced by H2O2, pretreatment WS-wsf and GS-wsf significantly enhanced cell viability. These results suggest that in addition to radical scavenging, WS-wsf and GS-wsf enhance cellular resistance to intracellular oxidative stress by activation of the Nrf-2/ARE pathway as confirmed by the increased Nrf2 protein level in the nucleus and increased heme oxygenase 1 (HO-1) mRNA expression. The roles of ferulic and vanillic acids as bioactive antioxidants in these fractions were also confirmed. In conclusion, our results indicated that WS-wsf and GS-wsf, which showed antioxidant activity in vitro, are also efficient antioxidants in a cell system protecting SH-SY5Y cells against both extracellular and intracellular oxidative stress. 相似文献