Open AccessHomogeneous enzyme immunoassay for macromolecular antigens using hybrid antibody
Author(s) -
Ashihara Yoshihiro,
Nishizono Isao,
Suzuki Hiromasa,
Kasahara Yasushi
Publication year - 1987
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.1860010112
Subject(s) - antibody , enzyme , immunoassay , antigen , chemistry , microbiology and biotechnology , biochemistry , dehydrogenase , homogeneous , enzyme assay , biology , immunology , physics , thermodynamics
A new homogeneous enzyme immunoassay for the determination of macromolecular antigens has been developed based upon competitive enzyme inhibition using hybrid antibody‐containing anti‐ligand and anti‐enzyme inhibitory antibodies. The hybrid antibody was prepared by the reaction of anti‐glucose‐6‐phosphate dehydrogenase (G6PDH) mouse IgG maleimide with anti‐human IgM goat IgG‐SH. In the absence of the antigen, the hybrid antibody inhibits the enzyme activity. On the other hand, in the presence of an excess amount of antigen, the hybrid antibody binds to the antigen and is unable to bind with the enzyme. The hybrid antibody inhibited 80% of the original activity of enzyme and saturated the inhibition of G6PDH within 10 min. The enzyme activity was proportional to the concentration of human IgM. The measurable range for IgM was 78 μg/ml to 1 mg/ml. Human IgG present in the serum did not affect this method.