The zwitterionic form of an amino acid having a negatively charged carboxyl group and a positively charged amino group.
| Member | Definition | Role |
|---|
| 1-aminocyclopropane-1-carboxylic acid | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of 1-aminocyclopropanecarboxylic acid; major species at pH 7.3. | 1-aminocyclopropanecarboxylic acid zwitterion; 1-aminocyclopropanecarboxylic acid |
| 2-amino-delta(2)-thiazoline-4-carboxylic acid | An amino acid zwitterion obtained from 2-amino-Delta(2)-thiazoline-4-carboxylic acid by the transfer of a proton from the carboxy group to the thiazoline nitrogen. The major species at pH 7.3. | 2-amino-Delta(2)-thiazoline-4-carboxylic acid zwitterion; 2-amino-Delta(2)-thiazoline-4-carboxylic acid |
| 2-methyltryptophan | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of 2-methyl-L-tryptophan; major species at pH 7.3. | 2-methyl-L-tryptophan zwitterion; 2-methyl-L-tryptophan |
| 2,3-diaminopropionic acid | An amino acid zwitterion of 3-aminoalanine where the 3-amino group is protonated. | 3-aminoalanine zwitterion; 3-aminoalanine |
| 3-amino-3-phenylpropionic acid | An amino-acid zwitterion arising form transfer of a proton from the carboxy to the amino group of 3-amino-3-phenylpropanoic acid; major species at pH 7.3. | 3-amino-3-phenylpropanoic acid; 3-ammonio-3-phenylpropanoate |
| 3-aminobutyric acid | An amino acid zwitterion that is 3-aminobutanoic acid in which a proton has been transferred from the carboxy group to the amino group. It is the major species at pH 7.3. | 3-aminobutanoic acid zwitterion; 3-aminobutanoic acid |
| 3-aminoisobutyric acid | Zwitterionic form of 3-aminoisobutyric acid arising from migration of a proton from the carboxy group to the amino group; major species at pH 7.3. | 3-aminoisobutanoic acid zwitterion; 3-aminoisobutyric acid |
| 3-hydroxyproline | An amino acid zwitterion obtained by transfer of a proton from the carboxy to the amino group of cis-3-hydroxy-D-proline; major species at pH 7.3 | cis-3-hydroxy-D-proline zwitterion; cis-3-hydroxy-D-proline |
| 3,3'-diiodothyronine | | 3,3'-diiodo-L-thyronine zwitterion; 3,3'-diiodo-L-thyronine |
| 3,5-dihydroxyphenylglycine | An amino acid zwitterion obtained by transfer of a proton from the carboxy to the amino group of (S)-3,5-dihydroxyphenylglycine. | (S)-3,5-dihydroxyphenylglycine zwitterion; (S)-3,5-dihydroxyphenylglycine |
| 4-amino-3-hydroxybutyric acid | Zwitterionic form of gamma-amino-beta-hydroxybutyric acid having an anionic carboxy group and a protonated amino group. | gamma-amino-beta-hydroxybutyric acid zwitterion; gamma-amino-beta-hydroxybutyric acid |
| 4-aminophenylalanine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of 4-amino-L-phenylalanine; major species at pH 7.3. | 4-amino-L-phenylalanine zwitterion; 4-amino-L-phenylalanine |
| 4-fluorothreonine | Zwitterionic form of 4-fluoro-L-threonine. | 4-fluoro-L-threonine zwitterion; 4-fluoro-L-threonine |
| 4-ketoproline | An amino acid zwitterion resulting from a transfer of a proton from the carboxy to the amino group of 4-oxo-L-proline; major species at pH 7.3. | 4-oxo-L-proline zwitterion; 4-oxo-L-proline |
| 5-aminovaleric acid | Zwitterionic form of 5-aminopentanoic acid having an anionic carboxy group and a protonated amino group. | 5-aminopentanoic acid zwitterion; 5-aminopentanoic acid |
| 5-hydroxytryptophan | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of 5-hydroxy-L-tryptophan; major species at pH 7.3. | 5-hydroxy-L-tryptophan zwitterion; 5-hydroxy-L-tryptophan |
| 7-aminocephalosporanic acid | Zwitterionic form of 7beta-aminocephalosporanic acid. | 7beta-aminocephalosporanic acid zwitterion; 7beta-aminocephalosporanic acid |
| 7-chlorotryptophan | Zwitterionic form of 7-chloro-L-tryptophan. | 7-chloro-L-tryptophan zwitterion; 7-chloro-L-tryptophan |
| 7-keto-8-aminopelargonic acid | Zwitterionic form of 8-amino-7-oxononanoic acid having an anionic carboxy group and a protonated nitrogen. | 8-amino-7-oxononanoic acid zwitterion; 8-amino-7-oxononanoic acid |
| agaritine | Zwitterionic form of agaritine. | agaritine zwitterion; agaritine |
| alanine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of alanine; major species at pH 7.3. | alanine zwitterion; alanine |
| allysine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of L-allysine; major species at pH 7.3. | L-allysine zwitterion; L-allysine |
| aminocaproic acid | Zwitterionic form of 6-aminohexanoic acid arising from migration of a proton from the carboxy group to the amino group; major species at pH 7.3. | 6-aminohexanoic acid zwitterion; 6-aminohexanoic acid |
| aminolevulinic acid | The zwitterion formed from 5-aminolevulinic acid by transfer of a proton from the carboxy group to the amino group. It is the major species present at physiological pH. | 5-aminolevulinic acid; 5-ammoniolevulinate |
| aminopenicillanic acid | Zwitterionic form of 6-aminopenicillanic acid arising from migration of a proton from the carboxy group to the 6-amino group; major species at pH 7.3. | 6-aminopenicillanic acid zwitterion; 6-aminopenicillanic acid |
| angiotensin ii | An amino acid zwitterion that is the dizwitterionic form of Ile(5)-angiotensin II having both carboxy groups deprotonated and the aspartyl amino group and arginine side-chain protonated. | Ile(5)-angiotensin II dizwitterion; Ile(5)-angiotensin II |
| angiotensin ii, des-phe(8)- | Dizwitterionic form of Ile(5)-angiotensin II (1-7) having both carboxy groups deprotonated and the aspartyl amino group and arginine side-chain protonated. | Ile(5)-angiotensin II (1-7) dizwitterion; Ile(5)-angiotensin II (1-7) |
| asparagine | Zwitterionic form of L-asparagine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. | L-asparagine zwitterion; L-asparagine |
| baclofen | | baclofen zwitterion; baclofen |
| beta-alanine | Zwitterionic form of beta-alanine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. | beta-alanine zwitterion; beta-alanine |
| beta-chloro-l-alanine | Zwitterionic form of 3-chloro-L-alanine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3 | 3-chloro-L-alanine zwitterion; 3-chloro-L-alanine |
| c(alpha)-formylglycine | An amino acid zwitterion obtained by transfer of a proton from the amino to the carboxy group of L-3-oxoalanine; major microspecies at pH 7.3 (according to Marvin v 6.2.0.). | L-3-oxoalanine zwitterion; L-3-oxoalanine |
| canaline | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of L-canaline; major species at pH 7.3. | L-canaline zwitterion; L-canaline |
| canavanine | L-Canavanine in zwitterionic form. | L-canavanine zwitterion; L-canavanine |
| carnosine | Zwitterionic form of carnosine. | carnosine zwitterion; carnosine |
| citrulline | Zwitterionic form of L-citrulline having an anionic carboxy group and a protonated amino group; major species at pH 7.3. | L-citrulline zwitterion; L-citrulline |
| cysteine | | cysteine zwitterion; cysteine |
| D-dopa | An amino acid zwitterion obtained from the transfer of a proton from the carboxy group to the amino group of D-dopa. Major microspecies at pH 7.3. | D-dopa zwitterion; D-dopa |
| d-glutamine | Zwitterionic form of D-glutamine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. | D-glutamine zwitterion; D-glutamine |
| dehydroalanine | An amino acid zwitterion resulting from a transfer of a proton from the carboxy group to the amino group of 2-aminoacrylic acid. | 2-aminoacrylic acid; 2-ammonioprop-2-enoate |
| delta-n-hydroxyornithine | An amino acid zwitterion obtained from N(5)-hydroxy-L-ornithine by transfer of a proton from the alpha-carboxy group to the amino group. | N(5)-hydroxy-L-ornithine zwitterion; N(5)-hydroxy-L-ornithine |
| diaminopimelic acid | A zwitterion that is derived from LL-2,6-diaminopimelic acid by deprotonation of both carboxylic acid groups and protonation of both amino groups. | (2S,6S)-2,6-diaminopimelic acid dizwitterion; LL-2,6-diaminopimelic acid |
| diazooxonorleucine | | 6-diazo-5-oxo-L-norleucine zwitterion; 6-diazo-5-oxo-L-norleucine |
| dimethylglycine | An amino acid zwitterion resulting from transfer of a proton from the carboxy to the amino group of N,N-dimethylglycine; major species at pH 7.3. | N,N-dimethylglycine zwitterion; N,N-dimethylglycine |
| diphthine | An amino acid zwitterion that is the conjugate base of cationic diphthine, formed via deprotonation of both carboxy groups and protonation of the primary amino group; major species at pH 7.3. | diphthinate |
| dopaquinone | Zwitterionic form of L-dopaquinone arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. | L-dopaquinone zwitterion; L-dopaquinone |
| gamma-aminobutyric acid | Zwitterionic form of gamma-aminobutyric acid having an anionic carboxy group and a protonated amino group. | gamma-aminobutyric acid zwitterion; gamma-aminobutyric acid |
| gamma-glutamyl hydroxamate | An amino acid zwitterion obtained by transfer of a proton from the carboxy to the amino group of glutamine hydroxamate; major species at pH 7.3. | glutamine hydroxamate zwitterion; glutamine hydroxamate |
| glucosaminic acid | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of 2-amino-2-deoxy-D-gluconic acid; major species at pH 7.3. | 2-amino-2-deoxy-D-gluconic acid zwitterion; 2-amino-2-deoxy-D-gluconic acid |
| glutamate-1-semialdehyde | Zwitterionic form of (S)-4-amino-5-oxopentanoic acid. | (S)-4-amino-5-oxopentanoic acid zwitterion; (S)-4-amino-5-oxopentanoic acid |
| glutamine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of L-glutamine; major species at pH 7.3. | L-glutamine zwitterion; L-glutamine |
| glycine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of glycine. | glycine zwitterion; glycine |
| histidine | Zwitterionic form of L-histidine having an anionic carboxy group and a protonated alpha-amino group. | L-histidine zwitterion; L-histidine |
| homocitrulline | An amino acid zwitterion of L-homocitrulline arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. | L-homocitrulline zwitterion; L-homocitrulline |
| homocysteine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of L-homocysteine; major species at pH 7.3. | L-homocysteine zwitterion; L-homocysteine |
| homocystine | Dizwitterionic form of homocystine arising from transfer of two protons from the carboxy to the amino groups; major species at pH 7.3. | homocystine zwitterion; homocystine |
| homoserine | Zwitterionic form of L-homoserine. | L-homoserine zwitterion; L-homoserine |
| hydroxythreonine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of 4-hydroxy-L-threonine; major species at pH 7.3. | 4-hydroxy-L-threonine zwitterion; 4-hydroxy-L-threonine |
| kynurenine | Zwitterionic form of L-kynurenine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. | L-kynurenine zwitterion; L-kynurenine |
| leucine | Zwitterionic form of L-leucine. | L-leucine zwitterion; L-leucine |
| levodopa | An amino acid zwitterion obtained from the transfer of a proton from the carboxy group to the amino group of L-dopa. Major microspecies at pH 7.3. | L-dopa zwitterion; L-dopa |
| lombricine | A zwitterionic form of L-lombricine where the carboxy and phosphate groups are anionic and the amino and guanidino groups are cationic; major species at pH 7.3. | L-lombricine dizwitterion; L-lombricine |
| methionine sulfoxide | Zwitterionic form of L-methionine (R)-S-oxide. | L-methionine (R)-S-oxide zwitterion; L-methionine (R)-S-oxide |
| methyl-3-tyrosine | An amino acid zwitterion resulting from a transfer of a proton from the carboxy to the amino group of 3-methyl-L-tyrosine; major species at pH 7.3. | 3-methyl-L-tyrosine zwitterion; 3-methyl-L-tyrosine |
| mimosine | An amino acid zwitterion resulting from a transfer of a proton from the carboxy group to the amino group of L-mimosine; major microspecies at pH 7.3 (according to Marvin v 6.2.0.). | L-mimosine zwitterion; L-mimosine |
| monoiodotyrosine | Zwitterionic form of 3-iodo-L-tyrosine having an anionic carboxy group and a protonated amino group; major species at pH 7.3. | 3-iodo-L-tyrosine zwitterion; 3-iodo-L-tyrosine |
| n-acetylglucosaminylasparagine | Zwitterionic form of N(4)-(beta-N-acetyl-D-glucosaminyl)-L-asparagine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. | N(4)-(beta-N-acetyl-D-glucosaminyl)-L-asparagine zwitterion; N(4)-(beta-N-acetyl-D-glucosaminyl)-L-asparagine |
| n-epsilon-acetyllysine | An amino acid zwitterion obtained via transfer of a proton from the carboxy to the amino group of N(6)-acetyl-L-lysine; major species at pH 7.3. | N(6)-acetyl-L-lysine zwitterion; N(6)-acetyl-L-lysine |
| n-methylalanine | Zwitterionic form of N-methyl-L-alanine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. | N-methyl-L-alanine zwitterion; N-methyl-L-alanine |
| n'-formylkynurenine | Zwitterionic form of N-formyl-L-kynurenine. | N-formyl-L-kynurenine zwitterion; N-formyl-L-kynurenine |
| n(alpha)-acetyllysine | An amino acid zwitterion obtained by transfer of a proton from the carboxy to the amino group of N(2)-acetyl-L-lysine; major species at pH 7.3. | N(2)-acetyl-L-lysine zwitterion; N(2)-acetyl-L-lysine |
| n(omega)-hydroxyarginine | Zwitterionic form of N(5)-[amino(hydroxyimino)methyl]-L-ornithine having an anionic carboxy group and a protonated alpha-amino group. | N(5)-[(E)-amino(hydroxyimino)methyl]-L-ornithine; N(5)-[(hydroxyamino)(imino)methyl]-L-ornithine; N(5)-[(Z)-amino(hydroxyimino)methyl]-L-ornithine; N(5)-[amino(hydroxyimino)methyl]-L-ornithine zwitterion; N(5)-[amino(hydroxyimino)methyl]-L-ornithine |
| nicotianamine | An amino acid zwitterion resulting from transfer of three protons from the carboxy to the amino groups of (S,S,S)-nicotianamine. One of two major microspecies at physiological pH. | (S,S,S)-nicotianamine trizwitterion; (S,S,S)-nicotianamine |
| nipecotic acid | The zwitterion resulting from the transfer of a proton from the carboxylic acid group to the amino group of (R)-nipecotic acid. | (R)-nipecotic acid zwitterion; (R)-nipecotic acid |
| omega-n-methylarginine | The zwitterion obtained from N(omega)-methyl-L-arginine by transfer of a proton from the carboxylic acid group to the alpha-amino group. | (2S)-2-amino-5-[[amino(methylimino)methyl]amino]pentanoic acid; N(omega)-methyl-L-arginine zwitterion; N(omega)-methyl-L-arginine |
| phenylalanine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of L-phenylalanine; major species at pH 7.3. | L-phenylalanine zwitterion; L-phenylalanine |
| poly-o-acetylserine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of O-acetyl-L-serine; major species at pH 7.3. | O-acetyl-L-serine zwitterion; O-acetyl-L-serine |
| proclavaminic acid | Zwitterionic form of proclavaminic acid. | proclavaminic acid zwitterion; proclavaminic acid |
| proline | The zwitterion formed from L-proline by proton transfer from the carboxy group to the ring nitrogen. It is the predominant species at physiological pH. | L-proline zwitterion; L-proline |
| pyrrolysine | Zwitterionic form of L-pyrrolysine. | L-pyrrolysine zwitterion; L-pyrrolysine |
| racemethionine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of methionine; major species at pH 7.3. | methionine zwitterion; methionine |
| s-adenosylhomocysteine | Zwitterionic form of S-adenosyl-L-homocysteine arising from migration of a proton from the carboxy group to the alpha-amino group; major species at pH 7.3. | S-adenosyl-L-homocysteine zwitterion; S-adenosyl-L-homocysteine |
| s-farnesylcysteine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of S-[(2E,6E)]-farnesyl-L-cysteine; major species at pH 7.3. | S-[(2E,6E)-farnesyl]-L-cysteine zwitterion; S-[(2E,6E)-farnesyl]-L-cysteine |
| selenomethionine | An amino acid zwitterion obtained by transfer of a proton from the carboxy to the amino group of L-selenomethionine; major species at pH 7.3. | L-selenomethionine zwitterion; L-selenomethionine |
| selenomethylselenocysteine | Zwitterionic form of Se-methyl-L-selenocysteine. | Se-methyl-L-selenocysteine zwitterion; Se-methyl-L-selenocysteine |
| serine ethanolamine phosphate | Dizwitterionic form of serine phosphoethanolamine having anionic carboxy and phosphate groups and both amino groups protonated. | serine phosphoethanolamine dizwitterion; serine phosphoethanolamine |
| symmetric dimethylarginine | An amino acid zwitterion obtained from N(omega),N'(omega)-dimethyl-L-arginine by transfer of a proton from the carboxylic acid group to the alpha-amino group. | N(omega),N'(omega)-dimethyl-L-arginine zwitterion; N(omega),N'(omega)-dimethyl-L-arginine |
| tetrahydrozoline | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of 2-methylserine; major species at pH 7.3 | 2-methylserine zwitterion; 2-methylserine |
| theanine | An amino acid zwitterion of N(5)-ethyl-L-glutamine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. | N(5)-ethyl-L-glutamine zwitterion; N(5)-ethyl-L-glutamine |
| thiocysteine | Zwitterionic form of 3-disulfanyl-L-alanine. | 3-disulfanyl-L-alanine zwitterion; 3-disulfanyl-L-alanine |
| threonine | Zwitterionic form of L-threonine arising from transfer of a proton from the carboxy to the amino group; major species at pH 7.3. | L-threonine zwitterion; L-threonine |
| thyroxine | The amino acid zwitterion formed from thyroxine by transfer of a proton from the carboxy group to the amino group. Major species at pH 7.3. | thyroxine zwitterion; thyroxine |
| triiodothyronine | The amino acid zwitterion formed from 3,3',5-triiodo-L-thyronine by tranfer of a proton from the carboxy group to the amino group. It is the major species at pH 7.3. | 3,3',5-triiodo-L-thyronine zwitterion; 3,3',5-triiodo-L-thyronine |
| triiodothyronine, reverse | Zwitterionic form of 3,3',5'-triiodo-L-thyronine. | 3,3',5'-triiodo-L-thyronine zwitterion; 3,3',5'-triiodo-L-thyronine |
| triiodothyronine, reverse | Zwitterionic form of 3,3',5'-triiodo-L-thyronine. | 3,3',5'-triiodo-L-thyronine zwitterion; 3,3',5'-triiodo-L-thyronine |
| tryptophan | An amino acid zwitterion obtained by transfer of a proton from the carboxy to the amino group of tryptophan; major species at pH 7.3. | tryptophan zwitterion; tryptophan |
| tyrosine | An amino acid zwitterion arising from transfer of a proton from the carboxy to the amino group of L-tyrosine; major species at pH 7.3. | L-tyrosine zwitterion; L-tyrosine |
| willardiine | Zwitterionic form of 3-(uracil-1-yl)-L-alanine having an anionic carboxy group and a protonated amino group. | 3-(uracil-1-yl)-L-alanine zwitterion; 3-(uracil-1-yl)-L-alanine |