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51.
Satoshi Nakamura Kunimasa Koga 《Biochemical and biophysical research communications》1977,78(2):806-810
By the method of differential scanning calorimetry, it was found that thermal stability of glucose oxidase was dependent on its redox states. The oxidized form showed an apparent denaturation temperature at 76°C and the denaturation enthalpy was approximately 865 kcal/mol. On reduction of the enzyme, the denaturation temperature increased by about 10°, but no significant change was seen in the denaturation enthalpy. The activation energies of the denaturation of the oxidized and the reduced enzymes were about 89 and 103 kcal/mol, respectively. These results may imply conformational changes in the catalytic turnover of this enzyme. 相似文献
52.
Hatanaka Akikazu; Kajiwara Tadahiko; Sekiya Jiro; Imoto Masaya; Inouye Satoshi 《Plant & cell physiology》1982,23(1):91-99
Isolated tea chloroplasts utilized linoleic acid, linolenicacid and their 13-hydroperoxides as substrates for volatileC6-aldehyde formation. Optimal pH values for oxygen uptake,hydroperoxide lyase and the overall reaction from C18-fattyacids to C6-aldehydes were 6.3, 7.0 and 6.3, respectively. Methyllinoleate, linoleyl alcohol and -linolenic acid were poor substratesfor the overall reaction, but linoleic and linolenic acids weregood substrates. The 13-hydroperoxides of the above fatty acidsand alcohol also showed substrate specificity similar to thatof fatty acids. Oxygen uptakes (relative Vmax) with methyl linoleate,linoleyl alcohol, linolenic acid, -linolenic acid and arachidonicacid were comparable to or higher than that with linoleic acid.In winter leaves, the activity for C6-aldehyde formation fromC18-fatty acids was raduced to almost zero. This was due tothe reduction in oxygenation. The findings presented here provideevidence for the involvement of lipoxygenase and hydroperoxidelyase in C6-aldehyde formation in isolated chloroplasts. (Received July 11, 1981; Accepted November 5, 1981) 相似文献
53.
Immunological responses of hamsters in the acquired immune state to Mycoplasma pneumoniae infection 总被引:1,自引:0,他引:1
E Hayatsu Y Kawakubo M Yayoshi M Araake M Wakai A Yoshida M Yoshioka Y Nishiyama 《Microbiology and immunology》1981,25(12):1255-1263
Protective effects of vaccination of hamsters against Mycoplasma pneumoniae infection, evaluated according to the recovery of mycoplasmas and histopathological changes in the respiratory tract after challenge infection, persisted for at least 6 months after the final vaccination. Serum antibody levels reached a maximum in the second week after the last vaccination and decreased markedly between the first and the third months, but increased again in sera obtained from animals given booster injections. Metabolism-inhibiting antibodies were detected in bronchial washings of animals showing high resistance obtained by vaccinal or passive immunization. Antiserum transfer was also effective for protection but cell-mediated immune responses were not demonstrated in any animals up to 6 months after the vaccination. Even after 10 months, suppression of both mycoplasmal proliferation and lung lesions was apparent, and a single dose of the vaccine induced a significant booster effect. These findings suggest that (1) humoral immunity is more important than cell-mediated immunity in resistance of hamsters to M. pneumoniae pneumonia, and (2) the antibody secreted in the respiratory tract may be involved in the local defense mechanisms. 相似文献
54.
Hiroshi Hitokoto Satoshi Morozumi Tomoaki Wauke Senzo Sakai Hiroshi Kurata 《Mycopathologia》1981,73(1):33-38
A total of 604 samples of about 7 different types of beans was examined to determine their mycological profiles, and suitability for use as solid substrates for mycotoxin production.All of the samples were collected from bean jam makers in Tokyo by the official food examiners.Genera Penicillium and Aspergillus were predominant, and genus Wallemia was also found commonly in all types of beans.Mycotoxin-producing Aspergillus strains were isolated from 52 samples of beans, approximately 9% of the total. The highest incidence of toxigenic Aspergillus (14.1%) was found in kidney beans. Red beans and peas inoculated with Aspergillus ochraceus were found to produce about 7 to 8 times more toxin than was obtained in a liquid medium, and red beans inoculated with A. versicolor produced more toxin than was obtained in yeast extract sucrose broth. Green peas inoculated with Fusarium graminearum produced about 8 times more T-2 toxin than was obtained in 1% peptone containing Czapek solution under comparable culture conditions. 相似文献
55.
Motoshige Kawata Satoshi Harada Baltazar Antonio Kiyoharu Oono 《Plant Cell, Tissue and Organ Culture》1992,28(1):1-10
Protoplasts were isolated from callus derived from a single homozygous seed of Oryza sativa L. var. Norin 8. Thirty protoclones were randomly selected and these showed variation in regeneration frequency ranging from 0–87% with an average of 52%. The potential for regeneration of each protoclone as reflected in the regeneration frequency was analyzed five times over a period of 250 days and showed that the protoclones can be classified into three types, namely: protoclones with high regeneration frequency; protoclones with low regeneration frequency, both of which maintained their respective levels of regeneration potential; and protoclones with gradually decreasing regeneration frequency. Secondary protoclones established from protoplasts isolated from some of these protoclones and regenerated 2–3 times for a period of 120 days also showed further reduction in regeneration frequency. The polypeptide composition analyzed by two dimensional gel electrophoresis suggests the presence of specific polypeptides related to regeneration potential. Analysis of ploidy level based on plant morphology and pollen size suggests the predominance of tetraploids among the regenerated plants. 相似文献
56.
Satoshi Hoshina 《BBA》1981,638(2):334-340
Temperature-dependent spectral changes of chlorophyll a (Chl a) incorporated into liposomes of two types of phosphatidylcholine are studied. When Chl a incorporated into the liposomes is cooled down to 5°C from the temperature of the gel-to-liquid crystalline phase transition of the lipid, the red shift as well as the increase in half-bandwidth of the red peak of Chl a are only slight. By measuring the difference spectra produced by substracting the absorption spectrum at the phase transition temperature of the lipid from that at lower temperature, it is shown that the component absorbing at longer wavelength (675–685 nm) than the peak of the red maximum (about 670 nm) significantly increases at the expense of the component absorbing at shorter wavelength (657–668 nm). The positions of positive and negative peaks depend on the temperature and the molar ratio of the lipid to Chl a. The absorbance change is most pronounced on cooling below the phase transition temperature of the lipid. The temperature-induced absorbance change is almost completely reversible. The results indicate that the aggregated forms of Chl a in liposomes can be spectrophotometrically detected in the gel phase of the lipid. 相似文献
57.
Satoshi Yanagisawa 《Human genetics》1980,53(2):183-188
Summary Three infants with different types of Y-chromosome abnomalies, including short- and/or long-arm deletion and mosaicism, are reported. The karyotypes of these patients were: 45,X/46,X,del(Y)/47,X,del(Y), del(Y) on peripheral lymphocytes and 45,X/46,X, del(Y) on gonadal tissue (case 1), 45,X/46,X,del(Y) (case 2), and 45,X/46,X,r(Y) (case 3). In case 1 the euchromatic segment on the deleted Y was distinctly larger than that of the father's Y.The three infants had no gross phenotypic anomalies except ambiguous genitals and low birth weight, and they were small for date. The histologic diagnosis in two of them was mixed gonodal dysgenesis (cases 1 and 2).The relationship between structural abnormalities of the Y chromosome and ambiguous genitals as well as male-determining factors is discussed. 相似文献
58.
Inhibitory effects of condiments and herbal drugs on the growth and toxin production of toxigenic fungi 总被引:2,自引:0,他引:2
Hiroshi Hitokoto Satoshi Morozumi Tomoaki Wauke Senzo Sakai Ikuko Ueno 《Mycopathologia》1979,66(3):161-167
The effects of thirteen kinds of powdered herbal drugs and seven kinds of commercial dry condiments on the growth and toxin production ofAspergillus parasiticus, A. flavus,A. ochraceus, andA. versicolor were observed by introducing these substances into culture media for mycotoxin production.Of the twenty samples tested, cinnamon bark completely inhibited the fungal growth, while the others only inhibited the toxin production.The inhibitors were easily extracted from the samples with solvents such as hot water, chloroform, or ethanol.The extracts from coptis, philodendron bark, mustard, green tea leaves, and zanthoxylum completely inhibited the aflatoxin production ofA. parasiticus, however, they had little or no inhibitory effect againstA. flavus. 相似文献
59.
Hiroshi Kihara Satoshi Saigo Hiroshi Nakatani Keitaro Hiromi Masao Ikeda-Saito Tetsutaro Iizuka 《BBA》1976,430(2):225-243
Kinetic studies of the isomerization reaction of horse heart ferricytochrome c between pH 8.5 and pH 12.1 have been carried out by using stopped-flow and rapid scanning stopped-flow techniques. Below pH 10, our results were in good agreement with the scheme proposed earlier (Davis, L. A., Schejter, A. and Hess, G. P. (1974) J. Biol. Chem. 249, 2624–2632). Above pH 10, another faster first-order process was observed, which suggested the existence of a transient species in the isomerization reaction between the species with and without a 695 nm band. The probable scheme of the isomerization reaction is considered to be where H denotes a proton, the colored forms are the species predominant at neutral pH with a 695 nm band and the noncolored forms are the species without a 695 nm band. The transient species has a small 695 nm absorbance which suggests that the sixth ligand is still Met-80, although the protein conformation might be different from that at neutral pH. 相似文献
60.
Tokuyuki Yoshida Kunihiko Morihiro Yuki Naito Atsushi Mikami Yuuya Kasahara Takao Inoue Satoshi Obika 《Nucleic acids research》2022,50(13):7224
Currently, gapmer antisense oligonucleotide (ASO) therapeutics are under clinical development for the treatment of various diseases, including previously intractable human disorders; however, they have the potential to induce hepatotoxicity. Although several groups have reported the reduced hepatotoxicity of gapmer ASOs following chemical modifications of sugar residues or internucleotide linkages, only few studies have described nucleobase modifications to reduce hepatotoxicity. In this study, we introduced single or multiple combinations of 17 nucleobase derivatives, including four novel derivatives, into hepatotoxic locked nucleic acid gapmer ASOs and examined their effects on hepatotoxicity. The results demonstrated successful identification of chemical modifications that strongly reduced the hepatotoxicity of gapmer ASOs. This approach expands the ability to design gapmer ASOs with optimal therapeutic profiles. 相似文献