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131.
Beata Bartodziejska Joanna Radziejewska-Lebrecht Maria Lipinska Yuriy A. Knirel Leonid O. Kononov Anatoly Y. Chernyak Hubert Mayer Antoni Rozalski 《FEMS immunology and medical microbiology》1996,13(2):113-121
Abstract In DOC-PAGE, lipopolysaccharide (LPS) of Proteus mirabilis R14/1959 (Rb-type) mutant showed a ladder-like migration pattern indicating the presence of a high molecular weight polysaccharide chain. The isolated polysaccharide, called T-antigen because of similarity with the T1 chain of Salmonella friedenau LPS, contained d -glucose, d -galacturonic acid ( d -GalA), and d -GlcNAc in molar ratios 2:1:1 and was structurally different from the O-antigen of the parental S-strain P. mirabilis S1959 but identical to the O-antigen of another S-strain Proteus penneri 42. The importance of a d -GalA( l -Lys)-containing epitope, most likely present in the core region of LPS, and of GalA present in the T-antigen chain in manifesting the serological specificity of P. mirabilis R14/1959 were revealed using rabbit polyclonal homologous and heterologous R- and O-specific antisera and the appropriate antigens, including synthetic antigens which represent partial structures of various Proteus LPS. 相似文献
132.
The unmasking of estradiol receptor in paraffin sections of Bouin's-fixed uterine tissue from ovariectomized gilts was attained with microwave treatment. Immunocytochemistry of the receptor was performed using a polyclonal or five monoclonal antibodies, two of which are commercially available, reacting with different domains of the protein and an amplified-peroxidase system for detection. With five of the antibodies, a predominance of nuclear staining was observed in cells of endometrial glands, while one monoclonal antibody (13H2), reacting with the receptor's domain E, showed a preference for the cytoplasmic receptor. In stroma, all antibodies detected more receptor in nuclei than in cytoplasm. In epithelium, the commercially available antibody H222, our monoclonals 13H2 and HT65, and the polyclonal antibody 402 demonstrated more receptor in cytoplasmic than in nuclear areas. In myometrium, the nuclei from longitudinal and ring muscles were definitely stained with the antibodies. We conclude that the accessibilities of the antibody epitopes of the receptor differ according to the functional uterine cell type.Dedicated to Professor Dr. Peter W. Jungblut on the occasion of his retirement 相似文献
133.
Sandrine Sagan Hubert Josien Philippe Karoyan Alié Brunissen Gérard Chassaing Solange Lavielle 《Bioorganic & medicinal chemistry》1996,4(12):2167-2178
The action of rotameric probes introduced either in position 7 or 8 in the sequence of substance P (SP) was investigated, i.e.
-tetrahydroisoquinoleic acid (Tic),
-fluorenylglycine (Flg),
-diphenylalanine (Dip), the diastereoisomers of
-1-indanylglycine (Ing) and
-benz[ƒ]indanylglycine (Bfi), the Z- and E-isomers of dehydrophenylalanine and dehydronaphthylalanine (ΔZPhe, ΔEPhe, ΔZNal, ΔENal) and
(Dmp). The aim of this study was the topographical characterization of the binding subsites of human NK-1 receptor expressed in CHO cells, especially the S7 and S8 subsites, corresponding to residues Phe7 and Phe8 of substance P. According to the binding potencies of these substituted-SP analogues, the S7 binding subsite is smaller than the S8 subsite: the S7 subsite accepts only one aromatic nucleus, while the S8 can accommodate three coplanar nuclei altogether. These findings are compatible with the idea that the S8 binding subsite may reside in the extracellular loops of the hNK-1 receptor. NK-1 agonists bind to human NK-1 receptor and activate the production of both inositol phosphates and cyclic AMP. As already quoted for septide, [pGlu6, Pro9]SP(6–11), discrepancies are observed between affinity (Ki) and activity (EC50) values for IPs production. While a weak correlation between Ki and EC50 values for IPs production could be found (r = 0.70), an excellent correlation could be demonstrated between their affinities (Ki) and their potencies (EC50) for cAMP production (r = 0.97). The high potency (EC50) observed for ‘septide-like’ molecules on PI hydrolysis, compared to their affinity is not an artefact related to the high level of NK-1 receptors expressed on CHO cells since a good correlation was found between EC50 values obtained for PI hydrolysis and those measured for spasmogenic activity in guinea pig ileum bioassay (r = 0.94).
According to the binding potencies of constrained analogues of phenylalanine, the S7 binding subsite of human NK-1 receptor is small, whereas the S8, which can accommodate three coplanar nuclei, might probably reside in the extracellular loop. The discrepancies observed between affinity (Ki) and activity (EC50) values for IPs production are not an artefact of CHO cells since a good correlation was found between EC50 for PI hydrolysis and those measured in guinea pig ileum bioassay. 相似文献
134.
Expression of heat shock genes in Clostridium acetobutylicum 总被引:1,自引:0,他引:1
135.
Abstract: Three independent studies have found that the density of dopamine D4-like receptors is elevated in postmortem brain striata in schizophrenia. This elevation has been questioned by a fourth study that used a different method and failed to detect a biphasic component when raclopride was used to compete against the binding of 1 n M [3 H]nemonapride to schizophrenia tissue. To test whether this competition method could distinguish between dopamine D2 and D4 receptors, the present study used mixtures of only these two cloned receptors, free of all other receptors. Using combinations of cloned dopamine D2 and D4 receptors, this competition method could not resolve these components up to a level of 48% D4 receptors. Thus, the objections raised by the findings of the fourth study, mentioned above, do not appear valid. Furthermore, the present results indicate that the data using such a competition method actually mask a manyfold marked elevation in the density of dopamine D4-like receptors in schizophrenia. 相似文献
136.
Modulation of Intracellular Cyclic AMP Levels by Different Human Dopamine D4 Receptor Variants 总被引:15,自引:0,他引:15
Vida Asghari Suparna Sanyal Saskia Buchwaldt rew Paterson Vera Jovanovic Hubert H. M. Van Tol 《Journal of neurochemistry》1995,65(3):1157-1165
Abstract: To investigate whether polymorphic forms of the human dopamine D4 receptor have different functional characteristics, we have stably expressed cDNAs of the D4.2, D4.4, and D4.7 isoforms in several cell lines. Chinese hamster ovary CHO-K1 cell lines expressing D4 receptor variants displayed pharmacological profiles that were in close agreement with previous data from transiently expressed D4 receptors in COS-7 cells. Dopamine stimulation of the D4 receptors resulted in a concentration-dependent inhibition of the forskolin-stimulated cyclic AMP (cAMP) levels. The potency of dopamine to inhibit cAMP formation was about twofold reduced for D4.7 (EC50 of ∼37 n M ) compared with the D4.2 and D4.4 variants (EC50 of ∼16 n M ). Antagonists block the dopamine-mediated inhibition of cAMP formation with a rank order of potency of emonapride > haloperidol = clozapine ≫ raclopride. There was no obvious correlation between the efficacy of inhibition of forskolin-stimulated cAMP levels and the D4 subtypes. Dopamine could completely reverse prostaglandin E2 -stimulated cAMP levels for all three D4 receptor variants. Deletion of the repeat sequence does not affect functional activity of the receptor. The data presented indicate that the polymorphic repeat sequence causes only small changes in the ability of the D4 receptor to block cAMP production in CHO cells. 相似文献
137.
Magali Basille Bruno J. Gonzalez Laurence Desrues †Myriam Demas ‡Alain Fournier Hubert Vaudry 《Journal of neurochemistry》1995,65(3):1318-1324
Abstract: The presence of receptors for the novel neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) has been recently demonstrated in the external granule cell layer of the cerebellum, a germinative matrix that generates the majority of cerebellar interneurons. In the present study, we have taken advantage of the possibility of obtaining a culture preparation that is greatly enriched in immature cerebellar granule cells to investigate the effect of PACAP on the adenylyl cyclase and phospholipase C transduction pathways. The two molecular forms of PACAP, i.e., 27-(PACAP27) and 38-(PACAP38) amino-acid forms of PACAP, induced a dose-dependent stimulation of cyclic AMP production in granule cells. The potencies of PACAP27 and PACAP38 were similar (ED50 = 0.12 ± 0.01 and 0.23 ± 0.07 n M , respectively), whereas vasoactive intestinal polypeptide (VIP) was ∼100 times less potent. PACAP27 and PACAP38 also induced a dose-dependent stimulation of polyphosphoinositide breakdown (ED50 = 19.1 ± 6.3 and 13.4 ± 6.0 n M , respectively), whereas VIP had no effect on polyphosphoinositide metabolism. The effect of PACAP38 on inositol phosphate formation was significantly reduced by U-73122 and by pertussis toxin, indicating that activation of PACAP receptors causes stimulation of a phospholipase C through a pertussis toxin-sensitive G protein. In contrast, forskolin and dibutyryl cyclic AMP did not affect PACAP-induced stimulation of inositol phosphates. Taken together, the present results demonstrate that PACAP stimulates independently the adenylyl cyclase and the phospholipase C transduction pathways in immature cerebellar granule cells. These data favor the concept that PACAP may play important roles in the control of proliferation and/or differentiation of cerebellar neuroblasts. 相似文献
138.
Sebastian Voigt Reinhart Gossrau Oliver Baum Klemens L?ster Werner Hofmann Werner Reutter 《The Histochemical journal》1995,27(2):123-132
Summary The 11-integrin is known to be a receptor for collagen and laminin mediating cell-matrix interactions. A monoclonal antibody, 33.4, which specifically inhibits the 1-integrin-mediated in vitro cell-collagen binding of rat hepatocytes and hepatoma-derived A-cells (Löster et al., 1994), was used to purify by immunoaffinity chromatography the 1-integrin subunit from rat liver in large quantities for inducing a polyclonal antiserum. In immunoblot analysis on membrane extracts of several rat organs this polyclonal antiserum recognized only a 190 kDa-band, suggesting that it is highly specific for the 1-integrin subunit. A sandwich-ELISA with monoclonal antibody 33.4 and the polyclonal antiserum against the 1-integrin subunit, respectively, enabled the quantitative expression pattern of the 1-integrin subunit to be studied in different rat organs. With the exceptions of brain (not detectable) and muscle (low concentration), the 1-integrin subunit was detectable in almost all organs of the digestive, respiratory and urogenital system as well as in lymphatic organs. The highest relative concentrations of 1-integrin subunit were found in uterus, lung and spleen, whereas in seminal vesicle, stomach, parotid gland, epididymis, kidney and liver only modest concentrations were evident. The organ distribution and localization of 1-integrin subunit were studied by immunohistochemistry with monoclonal and polyclonal antibodies. Immunoreactivity was present in the plasma membranes of all smooth muscle cells, vascular endothelial cells of many organs and fibrocyte-fibroblast sheaths in the heart and kidney. Since these cells are in close contact with collagen-containing basal membranes as well as reticular fibrils, strong evidence exists that in rat tissues the 1-integrin subunit is expressed at sites where collagen is present and might be involved in vivo in cell—ollagen binding.Dedicated to Professor Peter Sitte on the occasion of his 65th birthday 相似文献
139.
Matthias Kirsch Mun-Yong Lee Verena Meyer Annette Wiese Hans-Dieter Hofmann 《Journal of neurochemistry》1997,68(3):979-990
Abstract: There is increasing, although largely indirect, evidence that neurotrophic factors not only function as target-derived survival factors for projection neurons, but also act locally to regulate developmental processes. We studied the expression of ciliary neurotrophic factor (CNTF) and the CNTF-specific ligand-binding α-subunit of the CNTF receptor complex (CNTFRα) in the rat retina, a well-defined CNS model system, and CNTF effects on cultured retinal neurons. Both CNTF and CNTFRα (mRNA and protein) are expressed during phases of retinal neurogenesis and differentiation. Retina-specific Müller glia are immunocytochemically identified as the site of CNTF production and CNTFRα-expressing, distinct neuronal cell types as potential CNTF targets. Biological effects on corresponding neurons in culture further support the conclusion that locally supplied CNTF plays a regulatory role in the development of various retinal cell types including ganglion cells and interneurons. 相似文献
140.
Ryszard Russa Teresa Urbanik-Sypniewska Kristina Lindström Hubert Mayer 《Archives of microbiology》1995,163(5):345-351
Phenol-water extraction of Rhizobium loti NZP2213 cells allowed a simultaneous isolation of two structurally different lipopolysaccharides, from the aqueous (LPS-W) and phenol (LPS-P) phase that differed in their sodium doexycholate-PAGE pattern and composition. LPS-W showed a profile indicating an R-type LPS; LPS-P had a cluster of poorly resolved bands in the high-molecular-weight region. LPS-P contained large amounts of 6-deoxy-l-talose (6dTal), and a small amount of 2-O-methyl-6-deoxy-talose (molar ratio 30:1), both of which were completely absent in LPS-W. Methylation analysis gave only one major product, 2,4-di-O-methyl-6dTal, indicating that the O-chain is composed of a homopolymer of 1,3-linked 6dTal, having the methylated 6dTal (2-O-me-6dTal) probably localized at the non-reducing end of the O-chain. This homopolymeric O-chain was additionally O-acetylated, as evidenced by GC-MS and by 13C NMR analysis. The lipid A moieties of both LPS-W and LPS-P showed almost identical composition, with six, different 3-OH fatty acids and with two, so far not described, long-chain 4-oxo-fatty acids, all being amide-linked, and with 27-OH-28:0 as the main ester-linked fatty acid. Lipid A was of the lipid ADAG-type, i.e., having a (phosphorylated) 2,3-diamino-2,3-dideoxy-d-glucose-containing lipid A backbone. Lipid ADAG is widespread among species of the -2 group of Proteobacteria, but has so far not been encountered in any other rhizobial or agrobacterial species. 相似文献