Amino Acid Chart
Amino acids are the building blocks that make up all proteins, polypeptides and peptides. Each amino acid consists of a central carbon, known as the α-carbon, to which an amino group (-NH2), an acidic carboxyl group (-COOH) and an organic side chain (-R group) are bound. The R group, which differs for each amino acid, will determine its structure, polarity and pH.
Aliphatic Amino Acids with Hydrophobic Side Chain
Name | 3-Letter Symbol | 1-Letter Symbol | Formula | Molecular Weight | Isoelectric Point |
Alanine | ALA | A | C3H7N1O2 | 89.09 | 6.00 |
---|---|---|---|---|---|
Isoleucine | ILE | I | C6H13N1O2 | 131.17 | 5.94 |
Leucine | LEU | L | C6H13N1O2 | 131.17 | 5.98 |
Valine | VAL | V | C5H11N1O2 | 117.15 | 5.96 |
Aromatic Amino Acids with Hydrophobic Side Chain
Name | 3-Letter Symbol | 1-Letter Symbol | Formula | Molecular Weight | Isoelectric Point |
Phenylalanine | PHE | F | C9H11N1O2 | 165.19 | 5.48 |
---|---|---|---|---|---|
Tryptophan | TRP | W | C11H12N2O2 | 204.23 | 5.89 |
Tyrosine | TYR | Y | C9H11N1O3 | 181.19 | 5.66 |
Amino Acids with Neutral Side Chain
Name | 3-Letter Symbol | 1-Letter Symbol | Formula | Molecular Weight | Isoelectric Point |
Asparagine | ASN | N | C4H8N2O3 | 132.12 | 5.41 |
---|---|---|---|---|---|
Cysteine | CYS | C | C3H7N1O2S1 | 121.16 | 5.02 |
Glutamine | GLN | Q | C5H10N2O3 | 146.15 | 5.65 |
Methionine | MET | M | C5H11N1O2S1 | 149.21 | 5.74 |
Serine | SER | S | C3H7N1O3 | 105.09 | 5.68 |
Threonine | THR | T | C4H9N1O3 | 119.12 | 5.64 |
Amino Acids with Positive Charged Side Chain
Name | 3-Letter Symbol | 1-Letter Symbol | Formula | Molecular Weight | Isoelectric Point |
Arginine | ARG | R | C6H14N4O2 | 174.2 | 11.15 |
---|---|---|---|---|---|
Histidine | HIS | H | C6H9N3O2 | 155.16 | 7.47 |
Lysine | LYS | K | C6H14N2O2 | 146.19 | 9.59 |
Amino Acids with Negative Charged Side Chain
Name | 3-Letter Symbol | 1-Letter Symbol | Formula | Molecular Weight | Isoelectric Point |
Aspartic Acid | ASP | D | C4H7N1O4 | 133.1 | 2.77 |
---|---|---|---|---|---|
Glutamic Acid | GLU | E | C5H9N1O4 | 147.13 | 3.22 |
Unique Amino Acids
Name | 3-Letter Symbol | 1-Letter Symbol | Formula | Molecular Weight | Isoelectric Point |
Glycine | GLY | G | C2H5N1O2 | 75.07 | 5.97 |
---|---|---|---|---|---|
Proline | PRO | P | C5H9N1O2 | 115.13 | 6.30 |
Refer to chart below to explore structures, properties and types for each of the 20 standard amino acids.
Amino Acids | Structure | Abbr (3) | Abbr (1) | Enzymes | Codon | Class | Hydrophobicity (pH 7) | Freq. in Proteins (max. 10) | pKa | pI | Chemical formula | Molar mass | IUPAC name | Other names | Appearance | Density | Melting point | Solubility in water |
Alanine | Ala | A | Alanine Aminotransferase | GCT, GCC, GCA, GCG | Aliphatic | 41 | 7.5 | 2.34 | 6.00 | C3H7NO2 | 89.094 | Alanine | 2-Aminopropanoic acid | white powder | 1.424 g/cm3 | 258 °C (496 °F; 531 K) (sublimes) | 167.2 g/L (25 °C) | |
Arginine | Arg | R | Arginase | CGT, CGC, CGA, CGG, AGA, AGG | Basic | -14 | 5.0 | 2.17 | 10.76 | C6H14N4O2 | 174.204 | (S)-2-Amino-5-guanidinopentanoic acid | 2-Amino-5-guanidinopentanoic acid | White crystals | 1.5±0.1 g/cm3 | 260 °C; 500 °F; 533 K | 14.87 g/100 mL (20 °C) | |
Asparagine | Asn | N | Asparagine Synthetase; Asparaginase | AAT, AAC | Amidic | -28 | 4.5 | 2.02 | 5.41 | C4H8N2O3 | 132.119 | Asparagine | 2-Amino-3-carbamoylpropanoic acid | white crystals | 1.543 g/cm3 | 234 °C (453 °F; 507 K) | 2.94 g/100 mL | |
Aspartic acid | Asp | D | Aspartic Protease; Aspartic Proteinase | GAT, GAC | Acidic | -55 | 5.0 | 1.88 | 2.77 | C4H7NO4 | 133.103 | 2-Aminobutanedioic acid | Aminosuccinic acid; Asparagic acid; Asparagini… | colourless crystals | 1.7 g/cm3 | 270 °C (518 °F; 543 K) | 4.5 g/L | |
Cysteine | Cys | C | Cysteine Protease; Cysteine Peptidase | TGT, TGC | Sulfur-containing | 49 | 2.0 | 1.96 | 5.07 | C3H7NO2S | 121.150 | Cysteine | 2-Amino-3-sulfhydrylpropanoic acid | white crystals or powder | 1.3±0.1 g/cm | 240 °C (464 °F; 513 K) decomposes | soluble | |
Glutamic acid | Glu | E | Glutamic Acid Decarboxylase | GAA, GAG | Acidic | -31 | 6.5 | 2.19 | 3.22 | C5H9NO4 | 147.130 | 2-Aminopentanedioic acid | 2-Aminoglutaric acid | white crystalline powder | 1.4601 (20 °C) | 199 °C (390 °F; 472 K) decomposes | 7.5 g/L (20 °C) | |
Glutamine | Gln | Q | Glutamine Synthetase | CAA, CAG | Amidic | -10 | 4.0 | 2.17 | 5.65 | C5H10N2O3 | 146.146 | Glutamine | L-Glutamine; (levo)glutamide; 2,5-Diamino-5-ox… | White crystalline powder | 1.47 g/cm3 (20 °C) | decomposes around 185°C | soluble | |
Glycine | Gly | G | Glycine Decarboxylase Complex; Glycine Hydroxymethyltransferase; Glycine N-Methyltransferase | GGT, GGC, GGA, GGG | Aliphatic | 0 | 7.0 | 2.34 | 5.97 | C2H5NO2 | 75.067 | 2-aminoacetic acid | 2-Aminoethanoic acid, Glycocoll | White solid | 1.1607 g/cm3 | 233 °C (451 °F; 506 K) (decomposition) | 24.99 g/100 mL (25 °C) | |
Histidine | His | H | Histidine Ammonia-Lyase; Histidine Decarboxylase; Histidine Acid Phytases | CAT, CAC | Basic | 8 | 2.0 | 1.82 | 7.59 | C6H9N3O2 | 155.157 | Histidine | 2-Amino-3-(1H-imidazol-4-yl)propanoic acid | colourless crystals | 1.4±0.1 g/cm3 | 287 °C | 4.19g/100g @ 25 °C | |
Isoleucine | Ile | I | L-Isoleucine 4-Hydroxlase; Isoleucine 2-Epimerase | ATT, ATC, ATA | Aliphatic | 99 | 5.5 | 2.36 | 6.02 | C6H13NO2 | 131.175 | Isoleucine | (2S,3S)-2-amino-3-methylpentanoic acid | waxy, shiny crystals | ?1.0±0.1 g/cm3 | 285.5 °C | soluble | |
Leucine | Leu | L | Leucine Dehydrogenase; Leucine Aminotransferase; Leucine Transaminase; Leucine Deacylase; Leucine Aminopeptidase | CTT, CTC, CTA, CTG, TTA, TTG | Aliphatic | 97 | 9.0 | 2.36 | 5.98 | C6H13NO2 | 131.175 | Leucine | 2-Amino-4-methylpentanoic acid | white crystals | 1.17 g/cm3 at 20 °C | 293 °C | soluble | |
Lysine | Lys | K | Lysine a-Ketoglutarate Reductase; I-Lysine Monooxygenase; I-Lysine Decarboxylase; Lysine Oxidase; Lysine 2,3-Aminomutase | AAA, AAG | Basic | -23 | 6.0 | 2.18 | 9.74 | C6H14N2O2 | 146.190 | (2S)-2,6-Diaminohexanoic acid (L-lysine); (2R)… | Lysine, D-Lysine, L-lysine, LYS, h-Lys-OH | colourless crystals | 1.1±0.1 g/cm 3 | 224.5 °C | 1.5 kg/L | |
Methionine | Met | M | Methionine Synthase; Methionine Aminopeptidase | ATG | Sulfur-containing | 74 | 2.5 | 2.28 | 5.74 | C5H11NO2S | 149.210 | Methionine | 2-amino-4-(methylthio)butanoic acid | White crystalline powder | 1.340 g/cm3 | 281 °C (538 °F; 554 K) decomposes | soluble | |
Phenylalanine | Phe | F | Phenylalanine Hydroxylase | TTT, TTC | Aromatic | 100 | 4.0 | 1.83 | 5.48 | C9H11NO2 | 165.192 | (S)-2-Amino-3-phenylpropanoic acid | L-Phenylalanine | White crystalline powder | 1.34 g/cm3 at 20 °C | 283 °C | soluble | |
Proline | Pro | P | Proline Dehydrogenase; Proline 3-Hydroxlase | CCT, CCC, CCA, CCG | Aliphatic | -46 | 5.0 | 1.99 | 6.30 | C5H9NO2 | 115.132 | Proline; Pyrrolidine-2-carboxylic acid | L-Proline | Transparent crystals | 1.35-1.38 g/cm3 at 25 °C | 205 to 228 °C (401 to 442 °F; 478 to 501 K) | soluble | |
Serine | Ser | S | Serine Protease; Serine Endopeptidase; Serine Racemase | TCT, TCC, TCA, TCG, AGT, AGC | Hydroxylic | -5 | 7.5 | 2.21 | 5.68 | C3H7NO3 | 105.093 | Serine | 2-Amino-3-hydroxypropanoic acid | white crystals or powder | 1.603 g/cm3 (22 °C) | 246 °C (475 °F; 519 K) decomposes | soluble | |
Threonine | Thr | T | Threonine Ammonia-Lyase; Threonine Deaminase; Threonine Dehydratase; Threonine Aldolase | ACT, ACC, ACA, ACG | Hydroxylic | 13 | 6.0 | 2.09 | 5.60 | C4H9NO3 | 119.120 | Threonine | 2-Amino-3-hydroxybutanoic acid | colourless crystals | 1.3±0.1 g/cm 3 | 256 °C (decomposes) | (H2O, g/dl) 10.6(30°),14.1(52°),19.0(61°) | |
Tryptophan | Trp | W | Tryptophan Synthase; Tryptophan 2,3-Dioxygenase | TGG | Aromatic | 97 | 1.5 | 2.83 | 5.89 | C11H12N2O2 | 204.229 | Tryptophan; (2S)-2-amino-3-(1H-indol-3-yl)prop… | 2-Amino-3-(1H-indol-3-yl)propanoic acid | White crystalline powder | 1.4±0.1 g/cm3 | 290.5 °C | Soluble: 0.23 g/L at 0 °C, 11.4 g/L at 25 °C | |
Tyrosine | Tyr | Y | Tyrosinase; Tyrosine Hydroxylase; Tyrosine Kinase; Tyrosine Decarboxylase | TAT, TAC | Aromatic | 63 | 3.5 | 2.20 | 5.66 | C9H11NO3 | 181.191 | (S)-Tyrosine | L-2-Amino-3-(4-hydroxyphenyl)propanoic acid | white crystals | 1.46 g/cm3 at 20 °C | 343 °C | .0453 g/100 mL | |
Valine | Val | V | L-Valine Dehydrogenase | GTT, GTC, GTA, GTG | Aliphatic | 76 | 6.5 | 2.32 | 5.96 | C5H11NO2 | 117.148 | Valine | 2-Amino-3-methylbutanoic acid | white crystalline solid | 1.316 g/cm3 | 298 °C (568 °F; 571 K) (decomposition) | soluble |