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991.
New monoclonal antibodies against gastric gland mucous cell-type mucins: a comparative immunohistochemical study 总被引:2,自引:0,他引:2
H. Ota J. Nakayama Masanobu Momose Makoto Kurihara Kazuhiko Ishihara Kyoko Hotta Tsutomu Katsuyama 《Histochemistry and cell biology》1998,110(2):113-119
The immunohistochemical reactivity of monoclonal antibodies raised against rat and pig gastric mucins (HIK1083, PGM36, and
PGM37) was investigated in normal gastrointestinal tracts obtained from fish, amphibians, reptiles, birds, and mammals (including
humans). These monoclonal antibodies exhibited highly selective reactivity with class III mucins, as identified by paradoxical
concanavalin A stain, in the gastrointestinal tract of vertebrates. All three monoclonal antibodies reacted with the mucous
neck cells and pyloric gland cells of amphibians, reptiles and mammals, the cardiac glands of reptiles and mammals, and Brunner’s
glands of mammls. The deep crypt secretory cells of the rat colon and certain goblet-type cells deep in crypts in the pig
colon differed from the above pattern only in that they did not show immunoreactivity with monoclonal antibody PGM36. These
data suggest that the development of class III mucin is a fundamental evolutionary characteristic of vertebrate gastric mucins.
These monoclonal antibodies should prove useful for the investigation of cell differentiation among gastrointestinal mucous
cells and for the biochemical analysis of gastrointestinal mucins in different species.
Accepted: 17 February 1998 相似文献
992.
Yoshiaki Nagata Taibo Yamamoto Masatsugu Ema Junsei Mimura Yoshiaki Fujii-Kuriyama Tomohiko Suzuki Takahiro Furukohri Kazuhiko Konishi Dai Sato Genichi Tajima Jun Nakamura 《Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology》1998,119(4):777-785
Sarcoplasmic reticulum (SR) Ca2+-ATPase of the scallop cross-striated adductor muscle was purified with deoxycholate and digested with lysyl endopeptidase for sequencing of the digested fragments. Overlapping cDNA clones of the ATPase were isolated by screening the cDNA library with an RT-PCR product as a hybridization probe, which encodes the partial amino acid sequence of the ATPase. The predicted amino acid sequence of the ATPase contained all the partial sequences determined with the proteolytic fragments and consisted of the 993 residues with 70% overall sequence similarity to those of the SR ATPases from rabbit fast-twitch and slow-twitch muscles. An outline of the structure of the scallop ATPase molecule is predicted to mainly consist of ten transmembrane and five ‘stalk’ domains with two large cytoplasmic regions as observed with the rabbit ATPase molecules. The sequence relationship between scallop and other sarco/endoplasmic reticulum-type Ca2+-ATPases is discussed. 相似文献
993.
Kazuhiko Fukuda Takehiro Shoda Hitoshi Morikawa Shigehisa Kato Hiroyuki Mima Kenjiro Mori 《Journal of neurochemistry》1998,71(5):2186-2192
Abstract: To gain insight into the molecular mechanism for nociceptin function, functional coupling of the nociceptin receptor expressed in Chinese hamster ovary (CHO) cells with phospholipase A2 (PLA2 ) was examined. In the presence of A23187, a calcium ionophore, activation of the nociceptin receptor induced time- and dose-dependent release of arachidonate, which was abolished by pretreatment of the cells with pertussis toxin (PTX). Immunoblot analysis using anti-Ca2+ -dependent cytosolic PLA2 (cPLA2 ) monoclonal antibody demonstrates that activation of the nociceptin receptor induces a time- and dose-dependent electrophoretic mobility shift of cPLA2 , suggesting that phosphorylation of cPLA2 is induced by the nociceptin receptor. Pretreatment of the cells with PD98059, a specific mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 1 inhibitor, or staurosporine, a potent inhibitor of serine/threonine protein kinases and tyrosine protein kinases, partially inhibited the nociceptin-induced cPLA2 phosphorylation and arachidonate release. These results indicate that the nociceptin receptor expressed in CHO cells couples with cPLA2 through the action of PTX-sensitive G proteins and suggest that cPLA2 is activated by phosphorylation induced by the nociceptin receptor via mechanisms partially dependent on p44 and p42 mitogen-activated protein kinases. 相似文献
994.
Hideo Kurosawa Kenjin Shiba Kazuyoshi Hirako Isao Ikeda 《Inorganica chimica acta》1996,250(1-2):149-154
Some (η3-crotyl) (2,5-dichlorophenyl)palladium(II) complexes containing phosphine and phosphite ligands Pd(η3-CH2CH-CHMe)(Ar)(PR3) (Ar = C6H3Cl2-2,5) were isolated as crystalline solids or generated in solution. These existed as a mixture of two geometrical isomers arising from a different way of risposition of the crotyl-methyl group and the aryl ligand. The electronic nature of the PR3 ligand controlled the relative rates of the interconversion between the two isomers and the reductive elimination of the complexes which released MeCH=CHCH2Ar and CH2=CHCH(Me)(Ar). Electron-withdrawing phosphite ligands were particularly effective in enhancing the reductive elimination rate, making the contribution of the isomerization path almost negligible and allowing the formation of two coupling products to be followed separately by spectroscopic means. The observations demonstrated the occurrence of C---C coupling between mutually cis carbon ligands in (η3-allyl)(hydrocarbyl)palladium(II) complexes. The η1-crotyl complex, (Pd(η1-CH2CH=CHMe)(Ar) (dppen) (dppen = cis-Ph2PCH=CHPPh2) was isolated and shown to exist as a sole regio-isomer in solution. Reductive elimination of this η1-crotyl complex gave MeCH=CHCH2Ar exclusively. 相似文献
995.
The effects of electron acceptors, inhibitors of electron flow and uncouplers and inhibitors of photophosphorylation on a state II to I transition were studied. 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU) did not inhibit the state II to I transition. By contrast, 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB), methyl viologen and antimycin A inhibited the transition indicating that the cyclic electron flow around photosystem I, but not the oxidation of electron carriers (such as plastoquinone), induced the state II to I transition. Uncouplers, but not inhibitors of photophosphorylation, inhibited the state transition suggesting that the proton transport through the cyclic electron flow was related to the transition. 相似文献
996.
Oh-oka Hirozo; Itoh Shigeru; Saeki Kazuhiko; Takahashi Yasuhiro; Matsubara Hiroshi 《Plant & cell physiology》1991,32(1):11-17
The FA/FB protein of the photosystem I complex was isolatedfrom spinach leaves in a native state by use of anaerobic systems.The protein contained 8.5 non-heme iron atoms and 8.0 acid-labilesulfur atoms per molecule, consistent with the current conceptthat it has two [4Fe-4S] clusters. Its absorption spectrum wasvery similar to those of bacterial-type ferredoxins. The ratioof the absorbance at 390 nm to that at 280 nm was 0.6, and themolar extinction coefficient at 390 nm was 32,000 M.cm.Theoxidation-reduction properties of the iron-sulfur clusters wereexamined by redox potentiometry and EPR spectroscopy. The twoclusters were distinguishable in terms of their oxidation-reductionmidpoint potentials; their Em values were determined to be about-470mV and-560 mV, respectively. (Received July 16, 1990; Accepted October 8, 1990) 相似文献
997.
The development of a coimmobilized mixed culture sys tem of aerobic and facultative anaerobic microorganisms in Ca-alginate gel beads and the production of useful metabolites by the system were investigated. A coimmobilized mixed culture system of Aspergillus awamori (obligate aerobe) and Saccharomyces cerevisiae (facultative anaerobe) in Ca-alginate gel beads was used as a model system, and ethanol production from starch by the system was used as a model production. Mold Asp. awamori is an amylolytic microorganism while yeast S. cerevisiae is an ethanol producer. The two microorganisms grew competitively in the oxygen-rich surface area of the gel beads because they had similar oxygen demands in aerobic culture conditions. Neither microorganism exhibited "habitat segregation" in the gel beads and leaked yeast cells grew aerobically without ethanol production in the broth. Ethanol productivity was low under these conditions.A more desirable coimmobilized mixed culture system of Asp. awamori and S. cerevisiae was established by adding Vantocil IB (a biocidal compound) to the production medium. The antimicrobial activity of Vantocil IB was more effective with S. cerevisiae than with Asp. awamori, so that a dense mycelial layer of Asp. awamori formed in the surface of the gel beads While S. cerevisiae grew densely in the more inner areas of the gel beads. Also, yeast cell leakace was repressed and ethanol productivity was improved. The system with Vantocil IB produced ethanol of 4.5 and 12.3 g/L from 16 and 40 g/L starch, respectively. A continuous culture using this system with Vantocil IB was also carried out, and a stable steady state could be maintained for six days without leakage of yeast cells and contamination. The selection of a factor suitable for producing "habitat segregation" enabled the development of a coimmobilized mixed culture system of an aerobe and a facultative anaerobe. In this study, total habitat segregation was used to denote a tendency to exhibit denser growth in different parts of one gel bead. 相似文献
998.
Tsutomu Kouyama Yoshiaki Kimura Kazuhiko Kinosita Akira Ikegami 《Journal of molecular biology》1981,153(2):337-359
The spatial location and orientation of the retinal chromophore in bacteriorhodopsin were estimated from a fluorescence energy transfer study. The energy donor used in this study was a fluorescent retinal derivative, which was obtained by partial reduction of the purple membrane with sodium borohydride, and the energy acceptor was the native chromophore remaining in the same membrane. Since bacteriorhodopsin forms a two-dimensional crystal with P3 symmetry in the purple membrane, and the membrane structure is maintained after the reduction, the rate of energy transfer from a donor to any acceptor existing in the same membrane can be calculated as a function of the location and orientation of the chromophores in the unit cell. Quantitative analyses of the fluorescence decay curve and the quantum yield, with various extents of reduction, enabled us to determine the most probable location and orientation. The result suggested that the chromophore was situated near the centre of the protein in such an orientation that the dipole-dipole interaction with neighbouring chromophores was close to minimum. 相似文献
999.
Kazuhiko Kosuda 《Genetica》1981,55(1):17-21
Selection experiments between a lac
+
wild type and a lac
–
mutant of Escherichia coli were conducted using a serial transfer prcedure at two levels of total sugar concentration, i.e., 0.750 g/l and 1.0 g/l. The relative frequencies of both genotypes were assayed every 48 hours, at the time of transfer and the frequency changes were followed for about four weeks. The frequency of lac
–
decreased steadily and it was eventually eliminated from the mixed populations in all replicate cultures. The regression of logit pt was shown to be not linear but curvilinear, indicating that fitness differentials are frequency-dependent. The selection is also probably density-dependent. 相似文献
1000.
The correlation between the ATP-dependent Ca2+ binding and the phosphorylation of the membranes from swine and bovine erythrocytes was studied. The Ca2+ binding was measured by using 45CaCl2, and the phosphorylation by [γ-32P]ATP was studied with the technique of SDS polyacrylamide gel electrophoresis. 200 mM NaCl and KCl markedly repressed the Ca2+ binding of swine erythrocyte membranes. The radioactivity of 32P-labelled membranes was revealed mainly in 250 000 dalton protein and a lipid fraction. NaCl and KCl also repressed the phosphorylation of the lipid which was identified as triphosphoinositide by paper chromatography. The membranes prepared from trypsin-digested erythrocytes completely retained the Ca2+-binding activity, and lost 30% of activity. The Ca2+-binding and ATPase activity of isolated membranes decreased to 55% and to 0%, respectively, by tryptic digestion. Neither the Ca2+ binding nor the phosphorylation of polyphosphoinositides were detected in bovine erythrocyte membranes.These results suggest that the formation of triphosphoinositide rather than the of membranes is linked to the ATP-dependent Ca2+ binding of erythrocyte membranes. 相似文献