PathwayStep2754 Amino Acid conjugation Authored: Jassal, B, 2005-03-10 15:37:26 Edited: Jassal, B, 2008-05-19 12:57:01 GENE ONTOLOGYGO:0006805 Reactome Database ID Release 43156587 Reactome, http://www.reactome.org ReactomeREACT_6971 Xenobiotics that contain either a carboxylic group or an aromatic hydroxylamine group are possible substrates for amino acid conjugation. Xenobiotics with a <i>carboxylic group</i> conjugate with an <i>amino group</i> of amino acids such as glycine, taurine and glutamine. The <i>hydroxylamine group</i> conjugates with the <i>carboxylic group</i> of amino acids such as proline and serine. The amino acid is first activated by an aminoacyl-tRNA-synthetase which then reacts with the hydroxylamine group to form a reactive N-ester. N-esters can degrade to form electrophilic nitrenium (R-N⁺-R') and carbonium (R-C⁺H₂) ions. The pyrolysis product of tryptophan, an N-hydroxy intermediate, can potentially form these reactive electrophilic ions. Conjugation of carboxylic acids