Competitive enzyme inhibition immunoassay of apolipoprotein A-I: use of monoclonal antibodies.
An original competitive enzyme inhibition immunoassay has been developed for determination of total apolipoprotein A-I (apo A-I) in serum and in plasma. This specific assay involves a single monoclonal antibody (F59 4A12 2F4, directed to the -COOH terminal region of the apo A-I molecule) and a stable secondary plasma standard. Delipidation of serum samples exposed no additional antigenic sites, which suggests that all the apo A-I molecules express the epitope detected by Mab 4A12 on the surface of the apo A-I-containing particles. Within- and between-run CVs were, respectively, 6.1% and 7.5% at a 1.47 g/L concentration of apo A-I, 7.1% and 8.2% at 1.21 g/L, and 6.5% and 7.3% at 1.80 g/L. Results (y) correlated with those obtained with an electroimmunoassay (x), in which we used a mixture of three monoclonal antibodies, including Mab 4A12, as follows: y = 250x - 7, r = 0.744, P less than 0.001.
Bekaert
E D
ED
CNRS-UA 524, Laboratoire de Biochimie, Paris, France.
Ayrault-Jarrier
M
M
Petit
E
E
Betourne
C
C
Robin
H
H
Polonovski
J
J
D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D016632:Apolipoprotein A-I; D001054:Apolipoproteins A / Q000097:blood* / Q000276:immunology; D004355:Drug Stability; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D005260:Female; D019791:Guanidine; D006146:Guanidines / Q000494:pharmacology; D006358:Hot Temperature; D006801:Humans; D007118:Immunoassay; D008297:Male; D011786:Quality Control; D013223:Statistics as Topic; D014508:Urea / Q000494:pharmacology
D000911:Antibodies, Monoclonal; D016632:Apolipoprotein A-I; D001054:Apolipoproteins A; D000939:Epitopes; D006146:Guanidines; D014508:Urea; D019791:Guanidine