J. Buggy et al., HUMAN GLUCAGON RECEPTOR MONOCLONAL-ANTIBODIES - ANTAGONISM OF GLUCAGON ACTION AND USE IN RECEPTOR CHARACTERIZATION, Hormone and Metabolic Research, 28(5), 1996, pp. 215-219
This paper describes the development and characterization of the first
monoclonal antibody specific for the recently cloned human glucagon r
eceptor (hGR), and its use in probing receptor structure and function.
We demonstrate specificity of one of the antibodies, CIV395.7A, by im
munofluorescence staining and immunoprecipitation analysis. In additio
n, CIV395.7A specifically competes with glucagon for the hormone bindi
ng site on the receptor, indicating that the antibody's specific recog
nition epitope overlaps with the receptor's hormone binding domain. As
a consequence, the mAB antagonizes glucagon-stimulated signal transdu
ction as assayed by in vitro cAMP accumulation. Binding inhibition stu
dies further reveal that the antibody specifically recognizes the huma
n and rat GR, but not mouse. Using hGR/glucagon-like peptide I recepto
r chimeras, we have localized the recognition epitope of the antibody
to the membrane-proximal half of the a mine-terminal extension of the
receptor, thus defining a domain on the receptor which is involved in
glucagon binding.