title: Early theories of protein structure.
mesh_terms: D000595:Amino Acid Sequence; D001671:Biochemistry / Q000266:history; D004151:Dipeptides; D010450:Endopeptidases; D049672:History, 19th Century; D049673:History, 20th Century; D011506:Proteins / Q000266:history*
chemical_list: D004151:Dipeptides; D011506:Proteins; D010450:Endopeptidases