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The sugar binding activity of MR60, a mannose-specific shuttling lectin, requires a dimeric state 总被引:1,自引:0,他引:1
MR60 is an intracellular membrane protein which has been shown to act as a
mannoside specific lectin and to be identical to ERGIC-53, a protein
characteristic of the endoplasmic reticulum-Golgi apparatus- intermediate
compartment, acting as a shuttle. According to its primary sequence, this
MR60/ERGIC-53 protein contains a luminal domain including the carbohydrate
recognition domain, a stem, a transmembrane segment and a cytosolic domain.
The endogenous MR60/ERGIC-53 protein is spontaneously oligomeric, (dimers
and hexamers). In this paper, we study the relationship between the
oligomerization state and the sugar binding capacity by using recombinant
proteins. The expression of the recombinant proteins was evidenced by
immunocytochemistry and by immunoprecipitation followed by SDS-PAGE
analysis. The full size recombinant protein binds mannosides and is
oligomeric, up to the hexameric form. Two truncated proteins lacking the
transmembrane and the cytosolic domains were prepared and characterized. A
long one, containing the cysteine 466 close to the C-terminal end of the
recombinant protein but lacking the cysteine 475, close to the C- terminal
end of the native protein, does bind mannosides and forms dimers but no
higher oligomeric forms. A shorter one, lacking both the cysteines 466 and
475, does not bind mannosides and does not form dimers or higher polymers.
The two cysteines in the carbohydrate recognition domain (C190 and C230)
are not involved in the stabilization of oligomers. In conclusion, this
study shows that the luminal moiety of MR60/ERGIC-53 contains a device
allowing both its oligomeric pattern and its sugar binding capability.
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The NHS Executive is keen to promote "hospital at home" services in Britain, as part of its philosophy of keeping more care in the community and also to relieve the increasing demand for hospital beds. One such service is the provision of intravenous antimicrobial therapy in the community. Yet, compared with the United States, where home or outpatient intravenous antimicrobial therapy programmes are well developed, experience in Britain and Europe is limited, reflecting a difference in cultural attitudes and healthcare structures between the two continents. Only a few units in Britain currently run home intravenous antimicrobial therapy programmes, and several issues need to be addressed if more treatment is to be provided outside hospital. These include an assessment of the need for community intravenous antibiotic treatment and which patient groups many benefit. The main motive for community intravenous treatment should be better patient care and not simply a reduction in healthcare costs. At present the pace of change is being set by a few clinical enthusiasts and by commercial organisations, whereas the NHS deserves a more organised strategy for purchasing treatment with intravenous antibiotics in the community. 相似文献
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Patterns of ribosomal RNA evolution in salamanders 总被引:4,自引:0,他引:4
Sequence comparisons are presented for four segments of the large subunit
of ribosomal RNA, including divergent domains D7a and D7b, portions of the
large divergent domains D2, D3, and D8, and evolutionarily conservative
sequences flanking divergent domains. These results resolve phylogenetic
relationships among exemplars of seven families of salamanders and the
three amphibian orders. Phylogenetic analysis confirms the prediction that
divergent domains feature the highest relative rates of base substitution
and length variation within the ribosome, but the divergent domains evolve
more slowly than nuclear noncoding DNA and the silent sites of structural
genes. Base substitutions demonstrate approximately twice as many
transitions as transversions and an uneven distribution among sites within
the divergent domains but no apparent bias in base composition. Length
mutations are primarily small insertions and deletions, with deletions
predominating. The divergent domains appear to be a good source of
phylogenetic information for evolutionary events occurring approximately
100-200 million years ago.
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Willeke MC van Roon-Mom Barry A Pepers Peter AC 't Hoen Carola ACM Verwijmeren Johan T den Dunnen Josephine C Dorsman GertJan B van Ommen 《BMC molecular biology》2008,9(1):84
Background
Huntington's disease is a progressive autosomal dominant neurodegenerative disorder that is caused by a CAG repeat expansion in the HD or Huntington's disease gene. Although micro array studies on patient and animal tissue provide valuable information, the primary effect of mutant huntingtin will inevitably be masked by secondary processes in advanced stages of the disease. Thus, cell models are instrumental to study early, direct effects of mutant huntingtin. mRNA changes were studied in an inducible PC12 model of Huntington's disease, before and after aggregates became visible, to identify groups of genes that could play a role in the early pathology of Huntington's disease. 相似文献78.
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