... hKAT -I, and also provides biochemical information about the s ubstrate specificity and cosubstrate inhibition of the enzyme. hKAT -I is inhibited by Tris under physiological pH conditions, w hichexplains ... transamination of kynurenine toKYNA, arbitrarily termed KAT- I and II , have b eendescribed in r at and human brains [14–16].In addition, KYNA is involved in maintaining physio-logical arterial ... (including, kynurenine, phenylalanine, tryptophan and tyrosine); sulfurcontaining amino a cids (including, methionine an d cysteine) and other aliphatic a mino acids (including, glutamine,leucine, histidine,...