Recombinant aequorin with a reactive cysteine residue for conjugation with maleimide-activated antibody.
The mutated recombinant aequorin with a reactive cysteine residue (Cys-aequorin) was highly purified and then conjugated with a maleimide-activated antibody without significant loss of luminescence activity. The conjugate ratio of Cys-aequorin to heavy chain of immunoglobulin G (IgG) was estimated to be 1:1. To test the bioluminescent immunoassay with aequorin-labeled antibody, alpha-fetoprotein (AFP), a serological marker of liver cancer, was used as a model analyte. The measurable range of AFP was 0.02 to 200 ng/ml with the coefficient of variation between 2.1 and 4.5%.
Inouye
Satoshi
S
Yokohama Research Center, Chisso Corporation, Kanazawa-ku, Yokohama 236-8605, Japan. sinouye@chisso.co.jp
Sato
Jun-ichi
J
D000331:Aequorin / Q000032:analysis* / Q000737:chemistry / Q000276:immunology; D000595:Amino Acid Sequence; D000906:Antibodies / Q000276:immunology*; D015374:Biosensing Techniques; D003545:Cysteine / Q000737:chemistry; D005822:Genetic Vectors / Q000235:genetics; D008163:Luminescent Measurements; D008301:Maleimides; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000032:analysis / Q000737:chemistry / Q000276:immunology
D000906:Antibodies; D008301:Maleimides; D011994:Recombinant Proteins; C043592:maleimide; D000331:Aequorin; D003545:Cysteine