Table 2.

Catalytic activity of ITIM‐mutated IDO1 transfectants

Sample	Kyn (μM) 6 hr	Kyn (μM) 16 hr
WT	5.825 ± 0.338	3.800 ± 0.212
Y115E	nd	nd
Y253E	nd	nd
Y115_253E	nd	nd

Kynurenine concentration, Kyn (μM), was assessed in the supernatants of untreated cells maintained 6 or 16 hr in culture in the presence of excess of Trp. The detection limit of the analysis was 0.05 μM. Concentrations below the detection limit are indicated as not detectable (nd). Data are means (±S.D.) of three experiments each performed in triplicate.