Table 2. Dissociation constants (K_d) of Phe and Trp binding to MtuDAH7PS_G232P and MtuDAH7PS_F227D determined from ITC.

Titrated ligand	Background ligand	MtuDAH7PSG232P Kd (μM)	MtuDAH7PSF227D Kd (μM)
Phe		17 ± 2 a	15.9 ± 0.9 c
Trp		150 ± 10 b	200 ± 20 d
Trp	Phe	210± 30 e	220± 20 f

^a28 μM of MtuDAH7PS_G232P with 900 μM Phe titrant.

^b30 μM MtuDAH7PS_G232P with 3 mM Trp titrant.

^c32 μM of MtuDAH7PS_F227D with 600 μM Phe titrant.

^d32 μM MtuDAH7PS_F227D with 5 mM Trp titrant.

^e24 μM MtuDAH7PS_G232P and a background of 50 μM Phe present in the cell with a 5 mM Trp titrant.

^f28 μM MtuDAH7PS_F227D and a background of 50 μM Phe present in the cell with a 5 mM Trp titrant.