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1.
Kato Yoji; Otsuki Tatsuya; Nakajima Tasuku; Ojima Kunihiko; Matsuda Kazuo 《Plant & cell physiology》1988,29(4):539-547
-Glucans (average mol wt, 1.3 ? 104) extracted with perchloricacid from 8-day-old suspension-cultured nonglutinous (var. Sasanishiki)and glutinous rice (var. Miyakogane) cells were compared. Theresults of hydrolysis by alpha;-, ß- and iso-amylasesand methylation analysis of the -glucans suggested that theirbasic structures are almost the same. These -glucans are highly-branchedpolysaccharides with an average chain length of about 910,with exterior and interior chain lengths of about 67and 23, respectively.
1Current address: Laboratory of Food Science, Faculty of Education,Hirosaki University, Hirosaki, Aomori 036, Japan. (Received April 27, 1987; Accepted March 2, 1988) 相似文献
2.
Solubilization and partial characterization of fatty acyl-CoA:sphingosine acyltransferase (ceramide synthetase) from rat liver and brain 总被引:1,自引:0,他引:1
Lignoceroyl-CoA:sphingosine lignoceroyltransferase, which catalyzes synthesis of lignoceroylsphingosine, the ceramide that is a major component of sphingolipids in mammalian tissues, has been solubilized from microsomes of rat brain and liver and partially purified. The microsomes were treated with 1 M sodium thiocyanate in N,N-bis(2-hydroxyethyl)glycine (Bicine) buffer containing 20% glycerol. The supernatant fraction obtained after centrifugation was fractionated by Sepharose CL-4B gel filtration. The ceramide synthetase activity was recovered in a small fraction containing high molecular weight proteins. Analysis of proteins and lipids indicated that the fraction was not simply a fragment of microsomes. The activity for synthesis of lignoceroylsphingosine, which is abundant in nervous system, was compared with that for the synthesis of stearoylsphingosine, which is more enriched in extraneural sphingolipids, in brain and liver microsomes. Despite the difference in relative abundance of molecular species of ceramides in these tissues, the activity for lignoceroylsphingosine synthesis was not more enriched in brain than in liver. 相似文献
3.
The xyloglucan present in the 24% KOH extract of the cell wallsof suspension-cultured rice cells was characterized by fragmentationanalysis with Trichoderma viride cellulase and Aspergillus oryzaeß-D-glucosidase. The xyloglucan is composed mainlyof the following oligosaccharide units: Results showed that the xyloglucan of suspension-cultured ricecells is more extensively branched than is that of rice seedlings.Another structural characteristic of the former xyloglucan isthe presence of D-galactosyl-D-xylosyl side chains that arenot found in the latter. (Received June 15, 1984; Accepted January 11, 1985) 相似文献
4.
Two lines of the red and pale yellow cell suspension cultures, prepared fromPrunus x yedoensis Matsum. callus induced by Murashige and Skoog's (1962) basal medium supplemented with 2, 4-dichlorophenoxyacetic acid (2,
4-D, 1.0 mg/l), kinetin (0.1 mg/l) and sucrose (30 g/l), were maintained on Schenk and Hildebrandt medium as modified by Mitchell
and Gildow (1975). The red cell suspension culture produced cyanidin 3-monoglucoside, 5, 4′-dihydroxy-7-methoxyisoflavone
4′-glucoside (prunetrin), isoquercitrin, catechin, epicatechin, and procyanidin B-1, B-2, B-3 and B-4, while the pale yellow
cells produced only a small amount of catechin and epicatechin as main flavonoids. These flavonoid compounds found in the
red cell culture were present also in maturePrunus leaves.
Maximum growth and maximum amount of total phenol and proanthocyanidin (procyanidins) were obtained with 0.3 mg/l of both
2,4-D and kinetin. Maximum concentration of anthocyanin was also obtained with 0.3 mg/l 2, 4-D regardless of kinetin concentration.
Accumulation of proanthocyanidin was markedly stimulated by low concentrations of phosphate, which reduced growth by about
half, and also by high concentrations of inorganic nitrogen. Production of both anthocyanin and proanthocyanidin was reduced
by lowered nitrogen levels. Cell growth and production of all phenolics were inhibited when ammonium ion replaced nitrate
in the medium. 相似文献
5.
Pyrolysates of cyanocobalamin, thiamine hydrochloride, riboflavin, pyridoxine hydrochloride, and ascorbic acid were tested for mutagenicity in the histidine-requiring mutants Salmonella typhimurium TA98 and TA100. Each vitamin was sealed in a glass tube and heated at 100-600 degrees C in a muffle furnace. Methanol-chloroform extracts of the pyrolysate of each vitamin tested did not show any mutagenicity in either TA98 or TA100 without rat liver 9000 x g supernatant fraction (S9) added. In the presence of S9, the B-group vitamins (cyanocobalamin, thiamine hydrochloride, riboflavin, and pyridoxine hydrochloride) were all mutagenic in TA98 and TA100, with the highest activity among the vitamins tested found in the pyrolysate of cyanocobalamin. The pyrolysate of 0.25 mumole cyanocobalamin produced 3200 revertants, while the pyrolysates of 0.25 mumole thiamine hydrochloride and riboflavin produced only 910 revertants, and the pyrolysate of pyridoxine hydrochloride did not show any mutagenicity at that amount. The mutagenicity was generally more active to TA98 than to TA100, indicating that frameshift-type mutagens were contained in the pyrolysates. The pyrolysate of ascorbic acid did not show any mutagenic activity in either TA98 or TA100 under the present experimental conditions. 相似文献
6.
A significant characteristic in a swimming pattern of a lamprey is the generation of a constant phase lag along its body in spite of the wide range of undulation frequencies. In this paper, we discuss a mathematical treatment for coupled oscillators with time-delayed interaction and propose a model for the central pattern generator (CPG) of a lamprey to account for the generation of a constant phase relation, with consideration of the signal conduction time. From this model, it is suggested that the desired phase relation can be produced by long ascending connections from the tail to the neck region of the CPG. 相似文献
7.
Yoji Hara Panos Ioannou Anthi Drousiotou Goula Stylianidou Violetta Anastasiadou Kunihiko Suzuki 《Human genetics》1994,94(2):136-140
Sandhoff disease occurs in the Christian Maronite community in Cyprus, a community that established over a thousand years ago. Nowadays, this community comprises less than 1% of the whole population, and has been culturally and socially isolated. Cultured fibroblasts from a patient from this inbred group showed a -hexosaminidase subunit mRNA of apparently the normal size but of reduced quantity. A mutational analysis of cDNA obtained by polymerase chain reaction amplification of mRNA showed a deletion of A at nt 76 (counted from A of the initiation codon, ATG). The deletion results in a frame shift and a premature termination within 20 amino acids from the N-terminus of the normal mature enzyme protein. The patient was homozygous for the deletion. The 5-end of the gene showed many discrepancies from the previously published sequence. We consider that these differences are probably polymorphisms of little functional significance, because the patient's fibroblasts generate decreased but stable mRNA and because some of these base changes were also found in the genes from control fibroblasts. An extensive evaluation of the prevalence of this mutant allele in this community is being initiated. 相似文献
8.
Sato Yoji; Weil Max Harry; Tang Wanchun; Sun Shijie; Xie Jianlin; Bisera Joe; Hosaka Hidehiro 《Journal of applied physiology》1997,82(2):558-562
Sato, Yoji, Max Harry Weil, Wanchun Tang, Shijie Sun,Jianlin Xie, Joe Bisera, and Hidehiro Hosaka. EsophagealPCO2 as a monitor of perfusionfailure during hemorrhagic shock. J. Appl.Physiol. 82(2): 558-562, 1997.Measurement ofgastric wall PCO2(PgCO2) bytonometric method has emerged as an attractive option for estimatingvisceral perfusion during circulatory shock. However, gastric acidsecretion obfuscates the tonometric measurement. We, therefore,investigated the option of measuringPCO2 in the esophagus to minimizethese restraints. Hemorrhagic shock was induced in five Sprague-Dawleyrats, and five rats served as sham controls.PgCO2 wasmeasured with an ion-sensitive field effect transistor that wassurgically implanted into the gastric wall. Esophageal luminalPCO2(PeCO2) wasmeasured by a second ion-sensitive field effect transistor sensor.During hemorrhagic shock, mean aortic pressure declined from 150 to 50 mmHg. Gastric blood flow decreased from 58 to 12 ml · min1 · 100 g1 (21% of preshock) andesophageal blood flow from 44 to 7 ml · min1 · 100 g1 (16% of preshock).PgCO2simultaneously increased from 47 to 116 Torr andPeCO2 from 47 to 127 Torr. The increases inPgCO2 werehighly correlated with increases inPeCO2(r = 0.90). Esophageal tonometry may,therefore, serve as a practical alternative to gastric tonometry. 相似文献
9.
Cell walls of 4-day old rice seedlings were extracted successivelywith ammonium oxalate-oxalic acid, 4% KOH and 24% KOH. A rß-D-glucanpreparation and a xyloglucan preparation were isolated fromthe 4% KOH extract and 24% KOH extract, respectively. Methylationanalysis and enzymic degradation studies of the polysaccharidesshowed that the former was built up predominantly of repeating-oligosaccharideunits of 3-O-rß-cellobiosyl-D-glucose and 3-O-rß-cellotriosyl-D-glucosein a molar ratio of 2.6 : 1.0, and the latter was of repeating-oligosaccharideunits of -D-xylosyl-(16)-rß-D-glucosyl-(14)-[-D-xylosyl-(16)]-rß-D-glucosyl-(14)-D-glucose,-D-xylosyl-(16)-rß-D-glucosyl-(14)-D-glucose and cellobiose.
1 Present address: Department of Botany, Iowa State University,Ames, Iowa 50011, U.S.A. (Received August 29, 1981; Accepted January 12, 1982) 相似文献
10.
K Watanabe S Narimatsu I Yamamoto H Yoshimura 《The Journal of biological chemistry》1991,266(5):2709-2711
The oxygenation of an aldehyde, 11-oxo-delta 8-tetrahydrocannabinol to a carboxylic acid, delta 8-tetrahydrocannabinol-11-oic acid was catalyzed by cytochrome P-450 MUT-2 purified from hepatic microsomes of male ddN mice. The oxygenation mechanism was confirmed by the incorporation of oxygen-18 from molecular oxygen into the carboxylic acid formed. An aldehyde form but not a hydrated form of 11-oxo-delta 8-tetrahydrocannabinol may be a substrate for the cytochrome P-450. The oxygenation of aldehyde catalyzed by cytochrome P-450 might be a common metabolic reaction in biological systems, and should be considered as an additional role of cytochrome P-450 in biotransformation of endogenous compounds and xenobiotics. 相似文献