Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0024141 (systemic lupus erythematosus)
 44,322 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Before the identification of the major mitochondrial antigens of primary biliary cirrhosis as components of the 2-oxo-acid dehydrogenase enzyme family, mitochondrial autoantigens were believed to be extremely heterogeneous and were divided into nine subtypes termed M1 to M9. This classification was based on the data derived from the relatively nonspecific biochemical and immunological techniques that were available. After the cloning and definition of the major autoantigens, more than 95% of the sera of patients with primary biliary cirrhosis were found to react with components of the 2-oxo-dehydrogenase enzymes; these enzymes correspond to the old M2 classification. Two other "M" species, dubbed M4 and M9, have attracted significant attention because they have been postulated to be prognostic indicators and more recently have been tentatively identified respectively as sulfite oxidase (EC 1.8.3.1) and glycogen phosphorylase (EC 2.4.1.1). Indeed, patients with the "overlap syndrome" are reported to have antibodies to M4 and a poor prognosis, whereas patients with antibodies to M9 have a favorable prognosis. To address the significance and definition of M4 and M9, we performed in-depth studies of sera from 11 patients with the overlap syndrome, 75 patients with primary biliary cirrhosis, 19 chronic active hepatitis patients, 13 patients with primary sclerosing cholangitis, 10 patients with cholangiocarcinoma, 20 patients with systemic lupus erythematosus, 20 patients with alcoholic cirrhosis, 17 patients with scleroderma and 30 normal individuals, using techniques of ELISA, complement fixation, immunoblotting and enzyme inhibition. We report herein that we were unable to show any disease-specific reactivity toward the proposed M4 and M9 antigens.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:M4 and M9 antibodies in the overlap syndrome of primary biliary cirrhosis and chronic active hepatitis: epitopes or epiphenomena? 133 Aug 64

'Monospecific' antibodies directed against nuclear ribonucleoprotein (nRNP) and Smith (Sm) antigens from the sera of patients with mixed connective tissue disease (MCTD) and systemic lupus erythematosus (SLE) were used to isolate and purify the respective antigens from calf thymus nuclear extracts. The antibodies were allowed to interact with the nuclear antigens and the resulting complexes were purified by Protein-A-Sepharose and poly-U-Sepharose chromatography. When the Protein-A-Sepharose antigen-antibody complex was sequentially eluted with 20% and 60% ethylene glycol, 2 fractions could be identified, one containing antigenically active Sm and the other antigenically active Sm and nRNP. The nRNP fraction contained 5 major proteins with mol. wts ranging from 38,000 to 150,000. The Sm antigen had a mol. wt of 68,000 and was noted to 'co-purify' with the nRNP antigen. Amino acid analysis of the purified proteins demonstrated a high content of glycine, serine and acidic amino acid residues similar to previously described core proteins of heterogeneous nuclear RNP (hnRNP), a precursor to mammalian messenger RNA. Analysis of the RNA moiety following nuclease phosphorylase reactions demonstrated the presence of a RNA polynucleotide with a 'capped' structure at the 5' terminus, a feature consistent with the concept that the nRNP antigen is part of the hnRNP complex.
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PMID:The purification, characterization and amino acid analysis of nuclear ribonuclear protein and Sm antigens reacting with human autoimmune sera. 688 33