title: Carboxyl protection using salt formation for the synthesis of linear sequential polypeptides: synthesis of poly-(L-tyrosyl-L-glutamyl-L-alanylglycyl)glycine-1-14C ethyl ester.
mesh_terms: D000595:Amino Acid Sequence; D002247:Carbon Isotopes; D055598:Chemical Phenomena; D002621:Chemistry
chemical_list: D002247:Carbon Isotopes