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1.
The high resolution 1H and 13C nuclear magnetic resonance (NMR) spectra of galactosylceramides containing n-fatty acids and α-hydroxy fatty acids were recorded in dimethylsulfoxide solution with and without addition of D2O. From the coupling constants of the sugar ring protons, a 4C1 conformation can be deduced. In contrast to the conformation in aqueous solution, the C6 hydroxymethylene group is freely rotating around the C6C5 bond. In the ceramide residue all signals produced by protons linked to carbons bearing electronegative substituents could be attributed. The large difference in coupling constants of the methylene protons of C1′ to the C2′ methine proton of the sphingosine indicates a restricted rotation around the C1′C2′ bond. The assignments of the hydroxy and amino protons follow from the decoupling of the corresponding methine protons. 相似文献
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R Dabrowski 《Acta physiologica Polonica》1987,38(5):439-444
The effect of histamine (Hi) on thermal stability of triple helical structure of collagen alone and collagen-chondroitin-6-sulphate complex was studied. Hi increased the thermal stability of collagen and the complex in acidic pH and decreased it in neutral pH. 相似文献
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Acute edematous pancreatitis was induced in rats by iv infusion of caerulein (CR) in a supramaximal dose of 7.5 x 10(-6)g x kg-1 x hr-1 during 6 hr. The most important finding of our study was the marked decrease of protein and nonprotein thiol content in pancreatic tissue of rats with CR-induced acute pancreatitis (AP). Oxygen radicals as well as 4-hydroxyalkenals resulting from lipid peroxidation are believed to be at least partly responsible for this phenomenon. Covalent binding of excessive amounts of 4-hydroxyalkenals to pancreatic tissue protein sulfhydryl groups has been documented. Presented data suggest a serious disturbance of sulfhydryl compounds metabolism in pancreatic tissue of rats with CR-induced AP which may be of importance in the pathogenesis of the disease. 相似文献
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Zoonotic infections caused by several orthopoxviruses (OPV) like monkeypox virus or vaccinia virus have a significant impact on human health. In Europe, the number of diagnosed infections with cowpox viruses (CPXV) is increasing in animals as well as in humans. CPXV used to be enzootic in cattle; however, such infections were not being diagnosed over the last decades. Instead, individual cases of cowpox are being found in cats or exotic zoo animals that transmit the infection to humans. Both animals and humans reveal local exanthema on arms and legs or on the face. Although cowpox is generally regarded as a self-limiting disease, immunosuppressed patients can develop a lethal systemic disease resembling smallpox. To date, only limited information on the complex and, compared to other OPV, sparsely conserved CPXV genomes is available. Since CPXV displays the widest host range of all OPV known, it seems important to comprehend the genetic repertoire of CPXV which in turn may help elucidate specific mechanisms of CPXV pathogenesis and origin. Therefore, 22 genomes of independent CPXV strains from clinical cases, involving ten humans, four rats, two cats, two jaguarundis, one beaver, one elephant, one marah and one mongoose, were sequenced by using massive parallel pyrosequencing. The extensive phylogenetic analysis showed that the CPXV strains sequenced clearly cluster into several distinct clades, some of which are closely related to Vaccinia viruses while others represent different clades in a CPXV cluster. Particularly one CPXV clade is more closely related to Camelpox virus, Taterapox virus and Variola virus than to any other known OPV. These results support and extend recent data from other groups who postulate that CPXV does not form a monophyletic clade and should be divided into multiple lineages. 相似文献
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An hybrid experiment, composed of 1H-NMR total correlation spectroscopy (TOCSY) and rotating frame nuclear Overhauser enhancement spectroscopy (ROESY) steps, makes it possible to determine both the partial (disaccharide) sequences, and the sequential order, of whole linear and branched oligosaccharide chains. 相似文献
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Kitaru Suda Slawomir Filipek Krzysztof Palczewski Andreas Engel 《Molecular membrane biology》2013,30(6):435-446
Rhodopsin, the prototypical G-protein-coupled receptor, which is densely packed in the disc membranes of rod outer segments, was proposed to function as a monomer. However, a growing body of evidence indicates dimerization and oligomerization of numerous G-protein-coupled receptors, and atomic force microscopy images revealed rows of rhodopsin dimers in murine disc membranes. In this work we demonstrate by electron microscopy of negatively stained samples, blue native- and sodium dodecyl sulphate-polyacrylamide gel electrophoresis, chemical crosslinking, and by proteolysis that native bovine rhodopsin exists mainly as dimers and higher oligomers. These results corroborate the recent findings from atomic force microscopy and molecular modeling on the supramolecular structure and packing arrangement of murine rhodopsin dimers. 相似文献