Quantitation of apolipoprotein B-48 in triacylglycerol-rich lipoproteins by a specific enzyme-linked immunosorbent assay.
This paper describes the use of an antiserum, specific for apolipoprotein (apo) B-48, in a competitive, enzyme-linked immunosorbent assay (ELISA) for apo B-48 in triacylglycerol-rich lipoprotein (TRL) fractions prepared from fasting and post-prandial plasma samples. Previously we showed the antiserum to act as an effective immunoblotting agent following sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Its use in this ELISA indicates that the antiserum recognises the C-terminal region of the protein on the surface of lipoprotein particles. The ELISA had a sensitivity of less than 37 ng/ml and intra- and inter-assay coefficients of variation of 3.8% and 8.6%, respectively. There was no cross-reaction in the ELISA against serum albumin, ovalbumin, thyroglobulin, or apo B-100 (purified by immunoaffinity chromatography), and high lipid concentrations (as Intralipid) did not interfere. A low density lipoprotein fraction reacted in the ELISA but SDS-PAGE-Western blot analysis confirmed the presence, in the fraction, of a small amount of apo B-48, indicating the existence of low density dietary-derived lipoprotein particles. ELISA and SDS-PAGE-Western blot analysis were used to measure apo B-48 in 12 series of postprandial samples collected from 4 diabetic and 8 normal subjects, following test meals of varying fat content. The mean correlation between the two methods was r = 0.74. The mean fasting concentration of apo B-48 in the TRL fractions from 15 healthy men was 0.46 microgram/ml of plasma.
Lovegrove
J A
JA
Centre for Nutrition and Food Safety, School of Biological Sciences, University of Surrey, Guildford, UK.
Isherwood
S G
SG
Jackson
K G
KG
Williams
C M
CM
Gould
B J
BJ
D000918:Antibody Specificity; D053283:Apolipoprotein B-48; D001055:Apolipoproteins B / Q000097:blood* / Q000276:immunology; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005215:Fasting; D005502:Food; D006801:Humans; D007106:Immune Sera; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D012016:Reference Values; D014280:Triglycerides / Q000097:blood*
D053283:Apolipoprotein B-48; D001055:Apolipoproteins B; D007106:Immune Sera; D008074:Lipoproteins; D014280:Triglycerides