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121.
Relative Activities of NAD- and NADP-Isocitric Dehydrogenases in Bean Mitochondria Modified by Glycerol or NADP 下载免费PDF全文
Yukio Yamamoto 《Plant physiology》1969,44(2):262-266
Mitochondria from cotyledons of Vigna sesquipedalis (L.) Fruwirth (starchy seed) showed no NAD-isocitric dehydrogenase (NAD-IDH) activity by the methods which have been known to be useful for the detection of NAD-IDH in mitochondria of plants including castor bean and alaska pea. When the Vigna cotyledon mitochondria were treated with glycerol, NAD-IDH activity appeared and NADP-isocitric dehydrogenase (NADP-IDH) activity was inhibited. The inhibition of mitochondrial NADP-IDH by glycerol was overcome by the addition of excess NADP.On the other hand, NADP-IDH activity in the soluble fraction of cell components was only slightly inhibited by glycerol and no NAD-IDH activity was elicited.It was postulated that NADP-IDH in mitochondria is converted to NAD-IDH by glycerol and back to NADP-IDH with NADP by the alteration in the spatial configuration of the enzyme. However, there could be 2 proteins as the other possibility.The NADP-IDH in the soluble fraction which is not subject to such alteration is different from the mitochondrial NADP-IDH. 相似文献
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Characterization of Clostridium perfringens (welchii) Isolated from Market Poultry 总被引:4,自引:2,他引:2 下载免费PDF全文
Richard Yamamoto Walter W. Sadler Henry E. Adler George F. Stewart 《Applied microbiology》1961,9(4):337-342
Strains of Clostridium perfringens capable of producing heat-resistant spores, characteristic of the food-poisoning types, were not recovered in a random survey of feces and livers of market poultry. Favorable growth response with a known food-poisoning strain indicated that the media and methods employed were adequate. Spores produced in vitro from this strain survived at 100 C for several hours. Animal feeding experiments with this strain showed that heat-resistant spores (surviving for 1 hr at 100 C) could be readily demonstrated 24 hr after oral instillation of vegetative cells in mouse feces, but not in chicken feces. One experiment suggests that this strain might adapt to the environment of the intestinal tract of chickens, but not all of the spores recovered were as heat resistant as those of the parent culture. 相似文献
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Cultured cells ofThalictrum flavum take up berberine exogenously added to medium against the concentration gradient. This uptake was temperature-dependent and sensitive to plasma membrane-bound ATPase inhibitors such as sodium orthovanadate and diethylstilbestrol, indicating that the process is mediated by an energy-requiring system. The time-course of pH-shift during berberine uptake suggests the participation of a berberine-proton antiport system in the berberine uptake by the cultured cells. In addition, the existence of a specific transport system was suggested by the competitive inhibition of berberine uptake by berberine analogues, coptisine and jatrorrhizine. 相似文献
129.
Shin-Ichi Yamamoto 《Journal of plant research》1989,102(1):93-114
Gap characteristics and gap regeneration were studied in several climaxFagus crenata forests in Japan. 278 gaps were observed. Gaps covered 12% of the total land area of 20.05 ha. Gap density was 13.9 gaps
per ha and, mean gap size was 92.0 m2. Smaller gaps were much more frequent than larger ones. Gaps larger than 400 m2 were rare. Most gaps were created by the death of single trees. Canopy trees died more often standing or with broken trunks
than by uprooting, although uprooted trees were relatively abundant in the site with poor soil drainage and in the site on
upper slope. Differences of gap regeneration behaviour were recognized among tree species.F. crenata regenerates in gaps from saplings recruited before gap creation and can replace not only its own gaps but also gaps of other
species. Most species other thanF. crenata andMagnolia obovata could not regenerate in their own gaps. More successful regeneration ofF. crenata may occur in gaps smaller than 200 m2, althought it regenerated in a wide range of gap size. However, increased relative density ofF. crenata in the canopy layer seems to prevent its successful regeneration. Gap regeneration of other species did not clearly depend
on a species-specific gap size. 相似文献
130.
H Yamamoto M D Miller H Tsubota D I Watkins G P Mazzara V Stallard D L Panicali A Aldovini R A Young N L Letvin 《Journal of immunology (Baltimore, Md. : 1950)》1990,144(9):3385-3391
CD8+ CTL inhibit the replication of HIV and simian immunodeficiency virus of macaques (SIVmac) in PBL and, therefore, are likely to play an important role in containing the spread of the AIDS virus in infected individuals. We have generated a series of gag-specific lytic T lymphocyte clones from PBL: of an SIVmac-infected rhesus monkey. These T cell clones are CD3+CD8+ and are MHC class I-restricted in their target specificity. They are, therefore, CTL. Interestingly, all gag-specific CTL clones, as well as the gag-specific lytic activity of PBL of this monkey, demonstrated specificity for a single 25 amino acid fragment of the SIVmac gag protein. Moreover, they were restricted in their lytic function by a single MHC class I allele. These findings illustrate a powerful method for cloning AIDS virus-specific T lymphocytes and demonstrate a remarkably restricted epitope specificity of this AIDS virus-specific CTL response. 相似文献