Purification and partial characterization of the liver membrane endopeptidase which transforms glucagon into glucagon (19-29)

Glucagon (19-29) is a calcium pump inhibitory peptide which modulates the effect of glucagon on its target tissues. Using a specific radioimmunoassay for glucagon (19-29), we have previously shown that upon incubation with hepatic plasma membranes, glucagon was processed at the level of its Arp 17 -Arp 18 , dibasic site into the (19-29) C-terminal fragment. The endopeptidase responsible for this processing was extracted from liver plasma membranes using CHAPS as detergent and purified by an anion-exchange chromatography followed by a hydrophobic interaction chromatography and by a hydroxylapatite chromatography