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991.
Frank Löhr Markus Blümel Jürgen M. Schmidt Heinz Rüterjans 《Journal of biomolecular NMR》1997,10(2):107-118
A triple-resonance NMR technique suitable for the determination ofcarbonyl-related couplings in polypeptide systems is introduced. Theapplication of three novel pulse sequences to uniformly13C/15N-enriched proteins yields E.COSY-likemultiplet patterns exhibiting either one of the3J(Ci–1,Hi
), 3J(Ci–1,Ci
) and3J(Ci–1,Ci)coupling constants in the indirectly detected 13Cdimension, depending on the passive spin selected. The experiments aredemonstrated with oxidized flavodoxin from Desulfovibrio vulgaris. On thebasis of the J-values measured and the backbone -angles derived from ahigh-resolution X-ray structure of the protein, the three associated Karplusequations were reparametrized. The root-mean-square differences between theexperimental coupling constants and those predicted by the optimized Karpluscurves are 0.41, 0.33 and 0.32 Hz for3J(Ci–1,Hi
),3J(Ci–1,Ci
) and3J(Ci–1,Ci),respectively. The results are compared with the Karplus parameters previouslypublished for the same couplings. 相似文献
992.
A computer program (BBReader) was developed which performs an inverse search in theBioMagResBank database. Given (cross) peak positions of a protein, the program searchesfor atoms with matching chemical shifts and suggests possible assignments for user-specifiedhomo- and heteronuclear one- to three-dimensional COSY- and NOESY-type experiments.It can handle 1H, 13C and 15N spectra. Distance information from PDB files can be utilizedfor filtering possible NOESY cross peak assignments. 相似文献
993.
Expression of connexin43 mRNA in adult rodent brain 总被引:3,自引:0,他引:3
E. Simbürger Alexander Stang Marian Kremer R. Dermietzel 《Histochemistry and cell biology》1997,107(2):127-137
994.
A. Brehmer Werner Stach Heinz-Jürgen Krammer Winfried Neuhuber 《Histochemistry and cell biology》1997,109(1):87-94
Sequential nitric oxide synthase immunohistochemistry and nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd)
histochemistry in pig small intestinal wholemounts revealed a complete colocalisation of the two nitrergic markers in submucous
neurons. The external submucous plexus (ESP) contained nitrergic neurons throughout. In the internal submucous plexus (ISP)
we found a moderate number of nitrergic neurons in the duodenum, while they were rare in the jejunum and nearly absent in
the ileum. Combined NADPHd histochemistry and silver impregnation showed morphological ESP type III and VI neurons to be NADPHd
positive whereas ESP type II, IV and V neurons were NADPHd negative. Axons of ESP type III, IV and VI neurons were often observed
to enter interconnecting strands directed abluminally. ESP type II neurons projected mainly to the ISP. In special silver-impregnated
wholemounts containing both external muscle layers and the abluminal part of the submucous layer, i.e. the myenteric plexus
and the ESP, the great majority of impregnated axons within the interconnecting strands were observed to run between both
plexuses and did not enter the circular muscle layer. We conclude that ESP type III and VI neurons are nitrergic while ESP
type II, IV and V neurons are non-nitrergic. Furthermore, we assume that ESP type III, IV and VI neurons may represent a submucosal
input to the myenteric plexus.
Accepted: 26 August 1997 相似文献
995.
996.
M. Kasper T. Reimann U. Hempel K.-W. Wenzel A. Bierhaus D. Schuh V. Dimmer G. Haroske M. Müller 《Histochemistry and cell biology》1997,109(1):41-48
Caveolin is a major structural protein of caveolae, also known as plasmalemmal vesicles, which are particularly abundant
in type I pneumocytes and capillary endothelial cells of lung parenchyma. Here we demonstrate that caveolin expression in
the alveolar epithelium of rats and mini pigs is strikingly downregulated after irradiation-induced lung injury. Indirect
immunoperoxidase staining with polyclonal anti-caveolin antibodies, confirmed by double fluorescence studies with type I cell-specific
monoclonal anti-cytokeratin antibodies or lectins, revealed a dramatic loss of caveolin immunoreactivity in type I pneumocytes.
In contrast, caveolin expression increased in endothelial cells. Immunoblotting of lung homogenates from normal and irradiated
rats using specific anti-caveolin antibodies confirmed the presence of caveolin in normal tissue and its marked decrease of
expression in fibrotic tissue. The loss of caveolin as an important structural protein of caveolae in alveolar epithelial
cells may be an early indicator of serious type I cell injury during fibrogenesis. The increase of caveolin immunoreactivity
in endothelia of blood vessels may indicate that different types of caveolae and/or different regulatory mechanisms of caveolin
expression exist.
Accepted: 28 May 1997 相似文献
997.
Mariëtte P. C. van de Corput Roeland W. Dirks Wouter W. Wiegant Joop Wiegant Klaus Mühlegger A. K. Raap 《Histochemistry and cell biology》1997,108(4-5):359-364
Oestradiol has been conjugated to allylamine-dUTP with an 11-atom spacer to allow enzymatic incorporation of the label into
DNA sequences. In a comparative DNA and mRNA FISH study we have used DNA probes that were either labelled with digoxigenin,
biotin or oestradiol. Results show that oestradiol-labelled probes can detect DNA and RNA sequences in FISH equally well as
digoxigenin- and biotin-labelled probes. Further, no crossreactivity between the various hapten-specific antibodies and the
three haptens were observed. Binding of the rabbit anti-oestradiol antibody to endogenous oestrogen in various tissues was
not observed under the conditions tested. In view of the increasing demands for multi-colour DNA and mRNA FISH applications,
oestradiol is a welcome addition to the collection of haptens employed in FISH.
Accepted 20 June 1997 相似文献
998.
Effects of cadmium,copper, and zinc on growth and thiol content of aquatic hyphomycetes 总被引:3,自引:1,他引:2
The effects of cadmium, copper, and zinc on the growth of ten strains ofaquatic hyphomycetes were investigated. On a solid medium, Cd and Cu reducedradial growth of most strains by 50% at concentrations between150–400 µM; in a liquid medium, the strains were more sensitive.The inhibitory effects of zinc were much less severe. Two isolates(Articulospora tetracladia and Tetracladium marchalianum) from a copper-minestream were more resistant against copper than conspecific strains from anon-polluted stream. Heliscus lugdunensis and Varicosporium elodeaeresponded to Cd exposure, but not to Cu or Zn exposure, by increasedsynthesis of SH-containing compounds. Glutathione levels showed a unimodalresponse to increasing Cd and Zn exposure. With copper, glutathionedecreased at intermediate levels of contamination. In the presence of Cd, H. lugdunensis synthesized several unknown sulfur-rich substances that wereabsent or produced at reduced rates in control cultures. 相似文献
999.
An electrophoretic study of genetic variation at 11 loci was performedfor a population of European minnows, Phoxinus phoxinus (L.). Ten loci, EST-1
*, EST-2
*
EST-3
*,GPD-1
*,GPD-2
*,GPI-1
*,GPI-2
*,MPI
*,6PGD
* and PGM
* were polymorphic. IDH
*wasmonomorphic. The mean number of heterozygotic loci over all 176 fish was 3.05 ± 0.104(SE). Observed mean heterozygosity was 0.28±0.058(SE) and expected mean heterozygosity was 0.27±0.054(SE). EST-2
*, EST-3
* andPGM
* were not in Hardy-Weinberg equilibrium. Length,condition, parasite numbers or male breeding characters, i.e. red colorationand tubercles, were not influenced by single enzyme loci. 相似文献
1000.
SNARE Proteins-Why So Many,Why So Few? 总被引:1,自引:0,他引:1
Michal Linial 《Journal of neurochemistry》1997,69(5):1781-1792
Abstract: Both trafficking and secretion critically depend on accurate and specific membrane recognition and fusion. A key step in these processes is the assembly of a complex consisting of a small number of proteins, i.e., the exocytic core complex. In nerve terminals, this set consists of VAMP and synaptotagmin, which reside at membranes of synaptic vesicles, and syntaxin and SNAP-25 at the plasma membrane. In this survey, different secretory systems that depend on the exocytic core proteins are considered. The possibility that specificity in membrane recognition and fusion is achieved by the numerous variants of proteins of the exocytic core is discussed. Variability of the core complex proteins is determined by the complexity of gene families, isoform-specific localization, and posttranslational modifications. Basic biochemical properties depend on specific isoforms, and the possible protein-protein interactions are determined, in turn, by the compatibility of different isoforms. A correlation between specific variants and distinct biochemical or cellular properties is shown. The outcome of this survey is that heterogeneity in secretion may be dictated by the large number of possible combinations of variants of only a few proteins. 相似文献