Amino Acid Codes

Amino Acid Structure Chart and Reference Table

GenScript offers a variety of peptide synthesis services with both natural and non-standard/unnatural amino acids. To order our Custom Peptides and Peptide Library services through our online ordering system, refer to the following list of amino acid codes below. You can use either the single or multiple letter codes, but make sure to include braces if using the multiple code. You can also find symbols and molecular features of each natural amino acid in our Reference Table.

Name Single Letter Code Multiple Letter Code D-Amino Acid Code
Alanine A {ALA} {d-ALA}
Asparagine N {ASN} {d-ASN}
Cysteine C {CYS} {d-CYS}
Glutamine Q {GLN} {d-GLN}
Homocysteine {HCY} {d-HCY}
Homoserine {HSE} {d-HSE}
Leucine L {LEU} {d-LEU}
Methionine M {MET} {d-MET}
Norvaline {NVA} {d-NVA}
Penicillamine {PEN} {d-PEN}
Proline P {PRO} {d-PRO}
Threonine T {THR} {d-THR}
Tyrosine Y {TYR} {d-TYR}
Pyroglutamate {pGLU} {d-pGLU}
Phosphorylation (THR) {pTHR}
Phosphorylation (TYR) {pTYR}
Citrulline {CIT}
N-methylated Isoleucine {nme-ILE}
N-methylated Phenylalanine {nme-PHE}
N-methylated Serine {nme-SER}
N-methylated Tyrosine {nme-TYR}
Iso Aspartic Acid {iso-ASP}
2-Methyl Alanine {2-Me-ALA}
Acetylation at the side chain {Lys-Ac}
Methionine sulfone {Met(O)2}
Propargylglycine {Pra}
Selenocysteine {Sec}
Azido-Lysine {Lys(N3)}
Carboxyamidomethylated Cysteine {Cys(Cam)}
Arg(Me)2 asymmetrical {ADMA}
Beta-Alanine {Beta-Ala}
6-amino-hexanoic acid {Ahx}
2,3-Diaminopropionic Acid {Dap}
L-alpha-aminobutyric acid {ABU}
beta-cyclohexyl-L-alanine {Cha} {D-Cha}
Biotin Lysine {Lys(biotin)}
(L) 2-PAL {L-2-PAL} {d-2-PAL}
{Chg} {Chg} {D-Chg}
{L-3-Pal} {L-3-Pal} {D-3-Pal}
{L-4-I-Phe} {L-4-I-Phe} {D-4-I-Phe}
{L-4-Pal} {L-4-Pal} {D-4-F-Phe}