Various synthetic glucagon-related peptides have been studied with respect to the biological activity in man, and to the immunoreactivity toward two different glucagon antisera.
From the biological study and comparison with the results previously obtained, it appears that the lipolytic potency can be dissociated from other biological activities: The structure responsible for lipolysis is contained inside the [19-22] amino-acid sequence while the structure necessary for glycogenolytic and insulinogenic actions is located inside the [24-29] amino-acid sequence.
The radioimmunological studies show the presence of two anti genie sites inside the glucagon molecule: One (N-terminal + central portion) is also present in some catabolic fragments of glucagon circulating in blood and must also be present in the entero glucagon (GLI) molecule. This site appears to be the one most often bound by glucagon antisera.
