Alanine (Ala)
Arginine (Arg)
Aspartic acid (Asp)
Cysteine (Cys)
GABA (?-aminobutyric acid)
Glutamic acid (Glu)
Glycine (Gly)
Histidine (His)
Isoleucine (Ile)
Leucine (Leu)
Lysine (Lys)
Methionine (Met)
Phenylalanine (Phe)
Proline (Pro)
Serine (Ser)
Threonine (Thr)
Tyrosine (Tyr)
Valine (Val)