A Rapid Radioimmunoassay of Human Apolipoproteins C-Ii and C-Iii
- 1 January 1984
- journal article
- research article
- Published by Taylor & Francis in Scandinavian Journal of Clinical and Laboratory Investigation
- Vol. 44 (4), 291-297
- https://doi.org/10.3109/00365518409083810
Abstract
Apolipoprotein (apo) C-II is an activator of lipoprotein lipase, while apo C-III has the ability to inhibit apo C-II activated lipolysis. In order to study further the relationship between lipoprotein lipase mediated hydrolysis and the serum concentrations of apo C-II and apo C-III we have developed radioimmunoassays for these apolipoproteins. Apo C-II and apo C-III were isolated from very low density lipoproteins (VLDL) by ion exchange chromatography. Apo C-II was further purified by affinity-chromatography. The purity of the two proteins was determined to be > 98% by polyacrylamide gel electrophoresis and immunodiffusion. The purified apolipoproteins were used as antigens, assay standards and labels. Formalin-treated Staphylococcus aureus Cowan I was used for immunoprecipitation and were shown to give rapid uptake of immune complexes that could easily be harvested by centrifugation. The assays were shown to be sensitive (10 μg/l), specific, precise (inter- and intra-assay coefficients of variation below 10%), rapid (completed in less than 6 h) and simple to perform. Delipidation of serum and lipoproteins had no effect on the results, indicating that the immunologically active sites of apo C-II and apo C-III are exposed to the aqueous environment under assay conditions. Serum apo C-II and apo C-III levels of normolipidaemic subjects were approximately 25 mg/l and 110 mg/l respectively. Highly significant positive correlations were found between VLDL apo C-II and VLDL apo C-III, respectively, and VLDL triglycerides, VLDL cholesterol and total serum TG. There was also a highly significant correlation between the HDL cholesterol concentration and the HDL apo C-III concentration.Keywords
This publication has 19 references indexed in Scilit:
- Apolipoprotein C-II and C-III levels in hyperlipoproteinemiaMetabolism, 1979
- Hypertriglyceridemia Associated with Deficiency of Apolipoprotein C-IINew England Journal of Medicine, 1978
- Radioimmunoassay of Human Apolipoprotein CIIJCI Insight, 1977
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976
- Activation of highly purified lipoprotein lipase from bovine milkBiochemical and Biophysical Research Communications, 1975
- The use of protein A‐containing Staphylococcus aureus as a solid phase anti‐IgG reagent in radioimmunoassays as exemplified in the quantitation of α‐fetoprotein in normal human adult serumEuropean Journal of Immunology, 1974
- Cofactor activity of protein components of human very low density lipoproteins in the hydrolysis of triglycerides by lipoprotein lipase from different sourcesBiochemistry, 1973
- Inhibition of lipoprotein lipase by an apoprotein of human very low density lipoproteinBiochemical and Biophysical Research Communications, 1972
- Sur un dosage rapide du cholesterol lié aux α-et aux β-lipoprotéines du sérumClinica Chimica Acta; International Journal of Clinical Chemistry, 1960
- THE DISTRIBUTION AND CHEMICAL COMPOSITION OF ULTRACENTRIFUGALLY SEPARATED LIPOPROTEINS IN HUMAN SERUMJCI Insight, 1955