Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0220723 (PCA)
 4,687 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of administration of galactosamine (GalN) and glucosamine (GlcN) on the levels of UDP-sugars and hexose monophosphates in rat livers were studied by a variety of 31P NMR methods. The flux of metabolites in the liver was monitored by in vivo NMR and showed elevated levels of UDP-sugars, and even greater increases in resonances at 4.6 ppm for GlcN treatment and at 2.0 ppm for GalN treatment. The individual compounds corresponding to these changes were identified in PCA liver extracts by 31P-[1H] two-dimensional relay spectroscopy with a HOHAHA-type 1H spin-lock. This method of transferring proton magnetization allows for nearly all of the proton chemical shifts to be observed for the hexose moiety of a UDP-sugar present in a complex mixture. The UDP-sugars in the extracts from treated rats were predominantly UDP-hexosamines. Relay spectra were also used to determine that GalN-1-P was the major component (16.0 mumol/g of liver) of the GalN-treated liver, while both alpha and beta anomers of GlcNAc-6-P were readily identified as the major hexose monophosphates in the GlcN experiment. Spectra from the 1H dimension of relay experiments conducted on extracts were nearly superimposable on relay spectra obtained under the same conditions for mixtures of standard compounds of known structure. UDP-GlcN and UDP-GalN were not commercially available, but their presence was established in the extracts after GalN treatment by obtaining relay spectra for a mixture of the compounds produced in situ enzymatically, without purification.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Uridine diphospho sugars and related hexose phosphates in the liver of hexosamine-treated rats: identification using 31P-[1H] two-dimensional NMR with HOHAHA relay. 235 May 39

The denaturation of IgE immunoglobulin induced by heating at 56 degrees C or by treatment at low pH is inhibited in the presence of high concentrations of salts or hexoses. Between 50 and 100% of the IgE anaphylactic activity (PCA) of rat and mouse antisera is recovered after heating at 56 degrees C for 1,5 or 5 h, respectively, in 1 M MgSO4 or 2 M glucose, mannose or fructose. Anaphylactic activity of IgE monoclonal anti-DNP mouse antibody is equally preserved. The specific antigenic determinants of human and rat IgE myeloma proteins are also thermostable in these conditions. The addition of MgSO4 or glucose protects IgE anaphylactic antibodies against denaturation at pH 2. It is suggested that IgE denaturation is the consequence of interactions between molecules of immunoglobulin and that such interactions are diminished by steric hindrance in a medium containing high concentrations of ions or hexose molecules.
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PMID:Influence of the medium on the heat and acid denaturation of IgE. 665 41

A major antigen inducing IgE in mice (DpI) was purified from a crude extract of Dermatophagoides pteronyssinus (D.p.) using Sephacryl S-200 gel filtration, DE52 ion exchange chromatography and isoelectric focusing. This antigen is not one of the major D.p. human allergens. Isoelectric focusing showed a single peak of PCA activity at pI 4.7. Activity followed a broader banding pattern on polyacrylamide gel electrophoresis (PAGE). The molecular weight of DpI estimated from Sephadex G-150 chromatography was 1.7 X 10(5) daltons. Molecular weight calculated from SDS-gels (reducing), however, was 3.7 X 10(4), which may indicate a molecule with a subunit composition. DpI contained no detectable hexose as measured by the phenol-sulfuric acid assay. PCA activity of DpI was stable at 98 degrees C and to treatment with 0.1 M sodium metaperiodate, but destroyed by pronase. DpI represents approximately one per cent of the total protein of crude extracts. Purified DpI displays a specific activity increase of 40 times that of the crude extract with the PCA test. DpI is capable of inhibiting 40% of the binding between crude extract and human IgE, but only at extremely high concentrations. Human IgE was 700 times more sensitive to D.p. crude extract than purified DpI by enzyme immunoassay.
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PMID:Purification of a murine IgE-inducing antigen extracted from the house dust mite, Dermatophagoides pteronyssinus. 704 69