Processing of Proglucagon to Glucagon-like Peptide-1 Authored: May, B, 2009-05-18 21:31:59 EC Number: 3.4.21 Edited: May, B, 2009-09-09 In secretory granules of intestinal L cells, proglucagon is proteolytically cleaved by prohormone convertase 1 (PC1) at two sites to yield GLP-1 (7-36) or GLP-1 (7-37). In humans almost all circulating GLP-1 is GLP-1 (7-36) amidated at the C-terminus. Experiments in knockout mice have shown that PC1 is necessary for cleavage. Carboxypeptidase E and peptidylglycine alpha-amidating monooxygenase may be involved in trimming and amidating the C-terminus. Pubmed12651102 Reactome Database ID Release 43381798 Reactome, http://www.reactome.org ReactomeREACT_23895 Reviewed: Bloom, SR, 2010-06-24 GLP-1