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1.
Compression wood (CW) contains higher quantities of β-1-4-galactan than does normal wood (NW). However, the physiological
roles and ultrastructural distribution of β-1-4-galactan during CW formation are still not well understood. The present work
investigated deposition of β-1-4-galactan in differentiating tracheids of Cryptomeria japonica during CW formation using an immunological probe (LM5) combined with immunomicroscopy. Our immunolabeling studies clearly
showed that differences in the distribution of β-1-4-galactan between NW (and opposite wood, OW) and CW are initiated during
the formation of the S1 layer. At this stage, CW was strongly labeled in the S1 layer, whereas no label was observed in the S1 layer of NW and OW. Immunogold labeling showed that β-1-4-galactan in the S1 layer of CW tracheids significantly decreased during the formation of the S2 layer. Most β-1-4-galactan labeling was present in the outer S2 region in mature CW tracheids, and was absent in the inner S2 layer that contained helical cavities in the cell wall. In addition, delignified CW tracheids showed significantly more labeling
of β-1-4-galactan in the secondary cell wall, suggesting that lignin is likely to mask β-1-4-galactan epitopes. The study
clearly showed that β-1-4-galactan in CW was mainly deposited in the outer portion of the secondary cell wall, indicating
that its distribution may be spatially consistent with lignin distribution in CW tracheids of Cryptomeria japonica. 相似文献
2.
3.
Using a digital imaging fluorescence microscope, we have detected a rapid transient increase in the free cytosolic calcium concentration in a single rat basophilic leukemia cell (RBL-2H3) after antigen stimulation. Calcium ions were transported very rapidly (within 1 s) after a lag time (about 10 s at 37 degrees C) from the external environment into the cytoplasm. On the basis of the present experimental results we conclude that the gradual changes in the overall fluorescence intensity observed for a cell suspension are due to the distribution of different lag times shown by different cells as to the calcium influx through membrane calcium channels. 相似文献
4.
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
5.
Phorbol myristate acetate inhibits increases in membrane fluidity induced by anti-IgM in B cells 总被引:3,自引:0,他引:3
J Mizuguchi N Utsunomiya M Nakanishi Y Arata 《Journal of immunology (Baltimore, Md. : 1950)》1988,140(8):2495-2499
Anti-IgM or anti-IgD stimulates B cells to induce increases in inositol phospholipid metabolism and intracellular free calcium concentration [( Ca2+]i). Anti-IgM also causes increases in membrane fluidity that occur more promptly than those in [Ca2+]i in resting B cells as well as BAL17 B lymphoma cells. However, other B cell activators such as LPS or PMA did not induce the membrane fluidity changes. Furthermore, sodium fluoride, which is considered to be an activator of the guanine nucleotide-binding protein, caused increases in membrane fluidity as well as increased [Ca2+]i or inositol phospholipid metabolism. Anti-IgM- or sodium fluoride-induced increases in membrane fluidity were inhibited by 20-min pretreatment of cells with PMA, but not by 24-h pretreatment. These results indicate that membrane fluidity changes are closely associated with increased [Ca2+]i after cross-linkage of membrane Ig and are regulated by protein kinase C in B cells. 相似文献
6.
Trimethylamine N-oxide respiration by aerobic photosynthetic bacterium, Erythrobacter sp. OCh 114 总被引:2,自引:0,他引:2
Erythrobacter sp. OCh 114, an aerobic photosynthetic bacterium, had trimethylamine N-oxide (TMAO) reductase activity, which increased when the culture medium contained TMAO. The reductase was located in the periplasm. The bacteria grew anaerobically in the presence of TMAO. These results suggested that Erythrobacter OCh 114 has the ability to reduce TMAO through the respiratory chain. The TMAO respiration system of this organism was different from those of facultative purple photosynthetic bacteria in two respects: (a) TMAO reductase did not have activity to reduce dimethyl sulfoxide and (b) soluble c-type cytochrome, cytochrome c551, and cytochrome b-c1 complex appeared to be involved. The photochemical activity, which is usually inoperative in the anaerobic cell suspension, was restored by TMAO, suggesting that the photosynthesis and the TMAO respiration share a common electron transfer chain. 相似文献
7.
In order to inquire into the molecular mechanism underlying the cooperative ligand binding to hemoglobin (Hb), conformational interaction at the interfaces between subunits are investigated on the basis of the atomic coordinates of human deoxy and human carbonmonoxy Hbs. Hypothetical intermediate structures are used, each of which is obtained from the procedure where one or more subunits in deoxy Hb are replaced by the corresponding CO-liganded subunits in carbonmonoxy Hb using the method of superimposition of two sets of atomic coordinates. When either alpha or beta subunit is substituted with the corresponding subunit in carbonmonoxy Hb, serious steric hindrances are produced between alpha 1FG4(92)Arg and beta 2C3(37)Trp or between alpha 1C6(41)Thr and beta 2FG4(97)His, all of which belong to the allosteric core affected directly by ligand binding. These steric hindrances become more serious when both alpha 1(alpha 2) and beta 2(beta 1) subunits are substituted. Therefore the change in the relative distance between iron atom and porphyrin by ligation results in strain in the C-terminal residues as an effect of the steric hindrance between the FG and C segments. However, no steric hindrance can be seen between subunits when the subunits in carbonmonoxy Hb are substituted with the corresponding subunits in deoxy Hb. The nature of the quaternary structural change from liganded to deoxy Hb seems to be different from that from deoxy to liganded Hb. 相似文献
8.
Carbohydrate structures of acetylcholine receptor from Torpedo californica and distribution of oligosaccharides among the subunits 总被引:8,自引:0,他引:8
H Nomoto N Takahashi Y Nagaki S Endo Y Arata K Hayashi 《European journal of biochemistry》1986,157(2):233-242
The structure of carbohydrates in acetylcholine receptor (AChR) from Torpedo californica is reported. Oligosaccharides released quantitatively from the whole molecule by N-oligosaccharide glycopeptidase digestion were fractionated by thin-layer chromatography and further purified by high-performance liquid chromatography. We show that more than 70% of the total oligosaccharide chains in Torpedo AChR are of the high-mannose type with the structures (Man)8(GlcNAc)2 and (Man)9(GlcNAc)2. The structure of these oligosaccharides were determined by proton nuclear magnetic resonance spectroscopy. These two types of oligosaccharides were shown to be distributed different proportions in all subunits of Torpedo AChR. We also show that several kinds of complex-type oligosaccharides comprising the rest of the carbohydrate in the protein exist mainly in the gamma and delta subunits. The structure of the carbohydrate moiety that is distributed on the four subunits of AChR was also examined by susceptibility to endo-beta-N-acetylglucosaminidase and sialidase and by binding affinity to lectins, e.g. concanavalin A, leucoagglutinating phytohemagglutinin, and wheat germ agglutinin. 相似文献
9.
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
10.
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