A reassessment of structure-function relationships in glucagon. Glucagon1-21 is a full agonist.
Glucagon1-21 has been prepared by treating native glucagon with carboxypeptidase A. Purified glucagon1-21 did not contain detectable methionine (less than 0.001 residue/mol) and the activity of the compound did not change after treatment with cyanogen bromide as has been shown with native glucagon. Glucagon1-21 stimulates hepatic adenylate cyclase activity to the same extent as native glucagon but with 0.1% the potency. Glucagon1-21 also displayed 0.1% the binding affinity of native glucagon to the glucagon receptor in hepatic membranes. Glucagon22-29 alone or in combination with glucagon1-21 did not activate adenylate cyclase or displase 125I-glucagon from its receptor. The finding that glucagon1-21 is a full agonist on adenylate cyclase is discussed in relation to the structure-function relationships required for the biological action of glucagon.
D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D005934:Glucagon / Q000378:metabolism* / Q000494:pharmacology; D010446:Peptide Fragments / Q000378:metabolism / Q000494:pharmacology; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism; D013329:Structure-Activity Relationship
D010446:Peptide Fragments; D011956:Receptors, Cell Surface; D005934:Glucagon; D000262:Adenylyl Cyclases