sequence of GLUC_RAT GLP-1 GLP-1(7-36) GLP-1(7-37) GLP-2 GRPP Gcg Glicentin Glicentin-related polypeptide Glucagon Glucagon-like peptide 1 Glucagon-like peptide 1(7-36) Glucagon-like peptide 1(7-37) Glucagon-like peptide 2 IMR:0002316 OXM OXY Oxyntomodulin UniProt:P06883 glucagon molecule_role glucagon