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91.
When tea leaves were homogenized and incubated, the volatileC6-compounds hexanal, cis-3-hexenal, cis-3-hexenol and trans-2-hexenalwere formed much more by summer leaves than by winter leavesof tea plants (Camellia sinensis). The enzymes lipolytic acylhydrolase (LAH), lipoxygenase, fatty acid hydroperoxide lyase(HPO lyase) and alcohol dehydrogenase (ADH) and an isomerizationfactor were responsible for the sequential reactions of C6-compoundformation from linoleic and linolenic acids in tea leaf lipids,and there were seasonal changes in their activities. The tealeaf enzymes were of 3 types: LAH and lipoxygenase, which hadhigh activities in summer leaves and low activities in winterleaves; ADH, which had low activity in summer leaves and highactivity in winter ones; and HPO lyase and the isomerizationfactor, which did not seem to have any effect on the rate ofC6-compound formation throughout the year. Changes in enzymeactivities were induced by shifts in the environmental air temperaturerather than by the age of the leaves. The combined activitiesof these enzymes determined the amounts and compositions ofthe volatile C6-compounds formed, which are the factors thatcontrol the quality of the raw leaves processed for green tea. (Received October 6, 1983; Accepted December 20, 1983) 相似文献
92.
Takanobu Anai Jiro Yamamoto Ichiro Matsuda Naoki Taniguchi Takahito Kondo Bunsaku Nagai 《Human genetics》1984,66(2-3):282-285
Summary Two siblings with renal tubular acidosis (RTA) and nerve deafness were examined. It was found by ammonium chloride and bicarbonate loading tests that the 6-year-old brother had a hybrid type of RTA and his 4-year-old sister, a distal type of RTA. Enzyme activity and amount of enzyme protein of carbonic anhydrase isoenzyme I and II in red blood cells, measured using an immunoadsorbent method, were normal in both cases. Although this indicated that the RTAs of these patients are not generated by the carbonic anhydrase deficiency, an investigation with renal tissue is necessary to arrive at a final conclusion. 相似文献
93.
94.
Lipoxygenase, Hydroperoxide Lyase and Volatile C6-Aldehyde Formation from C18-Fatty Acids during Development of Phaseolus vulgaris L. 总被引:1,自引:0,他引:1
Kidney bean plants (Phaseolus vulgaris) were found to have thecapability to produce C6-aldehydes (hexanal and hexenals) fromlinoleic and linolenic acids. The various organs tested hadlipoxygenase and hydroperoxide lyase activities responsiblefor the C6-aldehyde formation. Young leaves showed relativelyhigh activities for C6-aldehyde formation. However, the activitiesof the leaves decreased gradually with leaf expansion. Seedlingsand seeds containing cotyledons showed low activities for C6-aldehydeformation, because of the occurrence of an inhibitory factorin the cotyledons. The substrate specificity of the enzymeswas essentially the same among the various developmental stagesof leaves tested. (Received February 5, 1982; Accepted March 19, 1982) 相似文献
95.
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
96.
97.
Linolenic acid-[1-14C] was converted to 12-oxo-trans-10-dodecenoic acid, via 12-oxo-cis-9-dodecenoic acid by incubation with chloroplasts of Thea sinensis leaves. Thus, it was confirmed that linolenic acid is split into a C12-oxo-acid, 12-oxo-trans-10-dodecenoic acid, and a C6-aldehyde, trans-2-hexenal, leaf aldehyde, by an enzyme system in chloroplasts of tea leaves. 相似文献
98.
Subcellular localization of glycolytic key enzymes in germinating castor bean endosperm 总被引:2,自引:0,他引:2
Phosphofructokinase and pyruvate kinase activities in castorbean endosperm increased during germination. Subcellular localizationof pyruvate kinase and phosphofructokinase in germinating endospermtissues was studied by differential and sucrose density gradientcentrifugation techniques. Eighty five percent or more of thepyruvate kinase and phosphofructokinase activities were locatedin cytosol. The remaining activities were mainly detected inproplastids. (Received June 30, 1977; ) 相似文献
99.
S Naomi T Umeda T Iwaoka F Miura Y Kitamoto M Nakayama T Sato 《Endocrinologia japonica》1991,38(6):699-703
Plasma levels of immunoreactive atrial natriuretic peptide (IR-ANP) were measured with a specific radioimmunoassay in 19 undialysed patients with chronic renal failure. At the beginning, an extremely high level of plasma hANP (50 fmol/ml) seen in a patient was rejected with Smirnov's test and was excluded from further statistics. The plasma IR-ANP levels in these patients were significantly higher than those of 19 normal subjects matched with age and sex (10.9 +/- 1.6 vs 5.3 +/- 0.6 fmol/ml, mean +/- SEM, p less than 0.01), and positively correlated with mean blood pressure (r = 0.44, p less than 0.05) and the cardiothoracic ratio (r = 0.65, p less than 0.01), but did not correlate with creatinine clearance (r = -0.38, n.s.). Further, a significant correlation was observed between plasma IR-ANP and urinary protein output (r = 0.47, p less than 0.05). On the other hand, urinary protein output did not correlate significantly with variables such as mean blood pressure, the cardiothoracic ratio or creatinine clearance. Since it has been suggested that ANP enhances glomerular capillary permeability, increased ANP responding to volume overload in those patients may play an important role in increasing urinary protein excretion. 相似文献
100.
smg p21B/rap1B p21, a member of ras p21-like small GTP-binding protein superfamily, has been shown to be phosphorylated by cyclic AMP-dependent protein kinase (protein kinase A). We show here that this protein was also phosphorylated by cyclic GMP-dependent protein kinase (protein kinase G) in a cell-free system. The same serine residue (Ser179) in the C-terminal region was phosphorylated by both protein kinases G and A. The Km and Vmax values of smg p21B for protein kinase G were 5 x 10(-7) M and 4 x 10(-9) mol/min/mg, and those values for protein kinase A were 1 x 10(-7) M and 3 x 10(-8) mol/min/mg. 相似文献