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11.
Tanaka Osamu; Nakayama Yoshio; Emori Koji; Takeba Go; Beppu Toshio; Sugino Mamoru 《Plant & cell physiology》1994,35(1):73-78
Flower-inducing activity of lysine was examined in Lemna paucicostata151, a weakly responsive short-day plant, cultured on nitrogen-richmedium under long-day conditions (continuous light). Lemna paucicostata151 was homogenized in a solution of lysine and the homogenatewas centrifuged. The supernatant (lysine-containing extract)was added to nitrogen-rich medium after passage through a membranefilter to give various concentrations of lysine in the medium.Flowering was induced in plants grown for six days on mediumthat contained lysine at concentrations above 0.25 µM.In plants grown on medium that contained 1 µM lysine,a significant flowering response was observed on the fourthday of culture. However, the flower-inducing activity of lysinedisappeared when the lysine-containing extract was added tothe medium and the medium was then autoclaved, suggesting thatthe active principle is unstable to autoclaving. Among derivativesof lysine tested, lysine hydroxamate had the highest flower-inducingactivity and lysyl lysine had almost same activity as that oflysine. When added to the medium without homogenization withplant material, lysine and lysyl lysine had flower-inducingactivity but lysine hydroxamate did not induce flowering. (Received April 26, 1993; Accepted November 8, 1993) 相似文献
12.
Kawarabayasi Yutaka; Tanaka Ayako; Ohara Osamu; Arakawa Taku; Oka Masanori; Kato Hisako; Morita Miyo; Fujisawa Hisao 《DNA research》1994,1(6):289-296
To sequence a DNA segment inserted into a cosmid vector underthe directed sequencing strategy, we established a simple andrapid method for generating nested deletions which uses thein vitro packaging system of bacteriophage T3 DNA. The principleis based on the previous finding that this system can translocateany linear double-stranded DNA up to 40 kb into the phage capsidin a time-dependent manner and the encapsulated DNA becomesDNase-resistant. For this purpose, we constructed a cosmid vectorthat carries two different antibiotic selection markers at bothsides of the multiple cloning site, and after insertion of aDNA segment, the clone was linearized by -terminase at the cossite. After the packaging reaction in vitro followed by DNasetreatment, the encapsulated DNA was introduced into Escherichiacoli cells to give clones with unidirectional deletions by differentialantibiotic selection. Restriction and sequence analyses of deletionclones demonstrated that an ordered set of clones with nesteddeletions, ranging from less than 1 kb to 25 kb, was createdfrom either the end of the DNA segment. Thus, nested deletionclones that cover the entire region of a 40-kb cosmid insertcan be obtained by a single packaging reaction, and its restrictionmap can be simultaneously obtained. 相似文献
13.
Hanger Christopher C.; Presson Robert G. Jr.; Okada Osamu; Janke Steven J.; Watkins John J.; Wagner Wiltz W. Jr.; Capen Ronald L. 《Journal of applied physiology》1997,82(4):1283-1289
Hanger, Christopher C., Robert G. Presson, Jr., Osamu Okada,Steven J. Janke, John J. Watkins, Wiltz W. Wagner, Jr., and Ronald L. Capen. Computer determination of perfusion patterns in pulmonarycapillary networks. J. Appl. Physiol.82(4): 1283-1289, 1997.Individual pulmonary capillaries are notsteadily perfused. By using in vivo microscopy, it can readily bedemonstrated that perfusion continually switches between capillarysegments and between portions of the network within a single alveolarwall. These changes in capillary perfusion occur even when upstream pressure and flow are constant. Flow switching between capillary segments in the absence of hemodynamic changes in large upstream vessels suggests that capillary perfusion patterns could be random. Tocalculate the probability that perfusion patterns could occur bychance, it is necessary to know the total number of possible perfusionpatterns in a given capillary network. We developed a computer programthat can determine every possible perfusion pattern for any givencapillary network, and from that information we can calculate whetherperfusion of individual segments in the network is random. With theresults of the computer program, we have obtained statistical evidencethat some capillary segments in a network are nonrandomly perfused. 相似文献
14.
15.
Jun-Ichi Hayashi Osamu Gotoh Yusaku Tagashira 《Archives of biochemistry and biophysics》1980,205(1):27-35
Previous studies showed that stimulation of mouse mitochondrial ATPase activity of tumor cells, fetal liver, and adult brain by the uncoupler 2,4-dinitrophenol was markedly suppressed during incubation of the mitochondria with the uncoupler (J.-I. Hayashi et al., 1980, Biochem. Biophys. Res. Commun.92, 261–267). The present work showed the reason for this suppression. More than half the endogenous Mg2+ leaked from mitochondria of all tumor cells tested, and of fetal liver and adult brain during incubation with the uncoupler, while only about 30% of the endogenous Mg2+ leaked from mitochondria of other normal tissues. The effect of the uncoupler on Mg2+ leakage from liver mitochondria changed from the fetal to the adult type within about 30 min after birth. In hypotonic medium, normal liver mitochondria also lost more than half their total Mg2+ and concomitantly stimulation of their ATPase activity by uncoupler was considerably reduced. Exogenously added Mg2+ could reverse this reduced effect of the uncoupler on ATPase activity of mitochondria from normal tissues and tumor cells. These results show that the endogenous Mg2+ content of mitochondria directly affects the stimulation by uncoupler of ATPase activity of mitochondria from both normal tissues and tumor cells. Thus, mitochondria of all tumor cells tested, and of fetal liver and adult brain are leaky to Mg2+ during incubation with uncoupler and as a result of the leakage, the stimulatory effect of the uncoupler on their ATPase activity is greatly reduced. 相似文献
16.
Hydrolyses of N-trans-cinnamoylimidazole (1) and N-acetylimidazole (2) were accelerated by cyclohexaamylose (α-CA) and cycloheptaamylose (β-CA) at 25°C. The cleavage of the amide bond in 1 at pH 9.0 was accelerated by α-CA and β-CA by 28- and 38-fold, respectively, whereas the cleavage of the amide bond in 2 at pH 7.0 was accelerated by α-CA and β-CA by 50- and 28-fold, respectively. The β-CA-accelerated hydrolysis of 1 proceeded via binding, acylation of β-CA, and deacylation of β-CA trans-cinnamate, which is consistent with the pathway used by serine proteases. The deuterium oxide solvent isotope effects for acylation and deacylation steps indicate nucleophilic attack in acylation and general basic attack in deacylation. The present finding of the acceleration by cycloamyloses in the cleavages of amide bonds in 1 and 2 indicates that cycloamyloses are an excellent model for hydrolytic enzymes. 相似文献
17.
From dried leaves of Panax pseudo-ginseng subsp. himalaicus collected in Eastern Himalaya, new dammarane saponins, named pseudo-ginsenosides-F11 and -F8 were isolated along with the known Ginseng-root saponins, ginsenosides-Rb3, Rd and -Re. Pseudo-ginsenoside-F8 was proved to be a mono-acetyl-ginsenoside-Rb3 and the location of its acetyl group was established mainly by 13C NMR spectroscopy. Pseudo-ginsenoside-F11, was identified as the 6-O-α-rhamnopyransyl(1 → 2)-β-glucopyranoside of 3β,6α,12β,25-tetrahydoxy-(20S,24R)-epoxy-dammarane. The C-24 configuration of ocotillone and its related triterpenes was confirmed to be 24R excluding the recent comment by Lavie et al. 相似文献
18.
Masanori Fukushima Taketoshi Kato Ryuzo Ueda Kazuo Ota Shuh Narumiya Osamu Hayaishi 《Biochemical and biophysical research communications》1982,105(3):956-964
Cytotoxic actions of various prostaglandins were examined on L1210 mouse leukemia and several human leukemia cell lines, and prostaglandin D2 (PGD2) was found most active. PGD2 exerted a dose dependent inhibition of L1210 cell growth over 3.6 μ. At 14.3 μ growth was completely inhibited, and the number of viable cells remarkably decreased during culture. Microscopically the remaining cells showed degenerative changes with many vacuoles in their cytoplasm. The IC50 value of PGD2 on L1210 cell growth was calculated to be 6.9 μ (2.4 μg/ml), and at this concentration the DNA synthesis in 24 hr cultured cells was also decreased to a half of the level in the control cells. Such growth inhibition by PGD2 was also found at similar concentrations with several human leukemia cell lines such as NALL-1, RPMI-8226, RPMI-8402, and Sk-Ly-16. Among other prostaglandins tested, PGA2 showed a comparable, and PGE2 a less but significant growth inhibitory activity, while PGB2, PGF2α and PGI2 had no such effects on cell proliferation at 14.3 μ concentration. These results suggest a potential antineoplastic activity of PGD2. 相似文献
19.
Osamu Suzuki Hideki Hattori Makoto Sawada Toshiharu Nagatsu Naomasa Miki Haruhiro Higashida 《Neurochemistry international》1983,5(5):599-601
Mouse neuroblastoma × rat glioma NG108-15 hybrid cells contain a considerable amount of serotonin, and possess small but significant tryptophan hydroxylase activity. The results suggest that NG108-15 hybrid cells are serotonergic, in addition to the known cholinergic property. 相似文献
20.