preferred_name: an N-terminal (5-L-glutamyl)-[peptide] + an alpha-amino acid => 5-L-glutamyl amino acid + an N-terminal L-alpha-aminoacyl-[peptide]
preferred_name_lc: an n-terminal (5-l-glutamyl)-[peptide] + an alpha-amino acid => 5-l-glutamyl amino acid + an n-terminal l-alpha-aminoacyl-[peptide]
label: an N-terminal (5-L-glutamyl)-[peptide] + an alpha-amino acid => 5-L-glutamyl amino acid + an N-terminal L-alpha-aminoacyl-[peptide]
label_lc: an n-terminal (5-l-glutamyl)-[peptide] + an alpha-amino acid => 5-l-glutamyl amino acid + an n-terminal l-alpha-aminoacyl-[peptide]