Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A highly sensitive enzyme immunoassay system for the determination of cuprozinc-superoxide dismutase (Cu,Zn-SOD) in serum and urine by using beta-galactosidase as a labeling enzyme is reported. This assay had a greater sensitivity than that of previously reported radioimmunoassay methods and could measure from 0.05 to 10.0 ng of Cu,Zn-SOD with good reproducibility. Coefficients of variation for this enzyme immunoassay were 2.8-8.3% within a day and 5.6-16.1% between days. The average recoveries were 96-103% from sera and 96-105% from urines, respectively. Using this enzyme immunoassay, serum Cu,Zn-SOD concentrations increased significantly in patients with renal diseases and were slightly elevated in patients with liver diseases. Urinary Cu,Zn-SOD appeared to be the highest in all renal diseases. By immunofluorescent staining, Cu,Zn-SOD was located in the thickened portions of the glomerular basement membrane and proliferating mesangial cells of the kidney tissue from a patient with membranous glomerulonephritis.
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PMID:Enzyme immunoassay for cuprozinc-superoxide dismutase in serum and urine. 675 78

Immune complexes formed on the surface of glomerular epithelial cells (GEC) resolve slowly and therefore result in inflammation of the glomerular capillary wall, as in the case of human membranous glomerulonephritis. The metabolic defect in the processing of these complexes has not been identified. Immune complexes of cationic bovine gamma-globulin (BGG) and anti-BGG were formed on cultured GEC, and their intracellular processing was followed by tracing the fate of radioiodinated and colloidal gold-labeled anti-BGG in the endosomal, lysosomal, and extracellular compartments. It was determined that the complexes were rapidly internalized in endosomes (50% saturation achieved in 10 min). The rate of expulsion of complexes was much slower (50% of internalized complex exteriorized in approximately 90 min). Of the internalized anti-BGG, < 5% were proteolytically degraded, suggesting an inefficient lysosomal processing. This aspect was studied further by separating anti-BGG colloidal gold-loaded vesicles by low-speed centrifugation and quantitating the lysosomal enzymes acid phosphatase and beta-galactosidase. At equilibrium approximately 10% of total cellular enzymes was associated with the vesicles. It was concluded that immune complexes are rapidly internalized by the GEC. However, lysosomal processing of the complexes is slow and inefficient. The majority of accumulated endosomes route back to the plasma membrane and discharge their contents in the medium in the form of free antibody.
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PMID:Intracellular processing of immune complexes formed on the surface of glomerular epithelial cells. 751 43