Steady state kinetic parameters for tyrosine and phenylalanine hydroxylation by <i>T. gondii</i> aromatic amino acid hydroxylases.

aConditions: Varied concentrations of 0–200 µM tyrosine or phenylalanine, 50 mM HEPES-NaOH, 10 µM ferrous ammonium sulphate, 500 µM NADH and 500 µM 6-MPH4 (pH 7.5 and 32°C). The error given is the SEM of two or three separate experiments performed in duplicate or triplicate. bData taken from (20), oxidation. The activity PheH with tyrosine is so low that an accurate value could not be measured due to extremely low activity. nd = not detected.