2.6.1.38 0.0015 - substrate L-tryptophan 2.6.1.38 0.0019 - substrate L-histidine 2.6.1.38 0.002 - substrate L-tyrosine 2.6.1.38 0.0021 - substrate L-phenylalanine 2.6.1.38 0.866 - - 2.6.1.38 17.8 - -