Skip to main content
. 2018 May 25;8:8121. doi: 10.1038/s41598-018-26445-x

Table 2.

Transient-state kinetic constants for the reductive and oxidative half-reactions of AAO and its Phe397 variants.

k red
(s−1)
K d(Al))
(µM)
k red / K d
(s−1·mM−1)
app k ox1
(s−1·mM−1)
AAO 115 ± 3 31 ± 2 3710 ± 258 770 ± 40
F397Y 150 ± 3 41 ± 3 3660 ± 277 770 ± 70
F397W1 124 ± 3 292 ± 17 425 ± 10 689 ± 92
F397A 69 ± 1 61 ± 2 1130 ± 40 78 ± 4
F397L 87 ± 1 180 ± 7 483 ± 20 340 ± 10

The constants were measured using stopped-flow rapid spectrophotometry in 50 mM sodium phosphate (pH 6.0) at 12 °C under anaerobic conditions. 1The F397W constants for the first phase of the oxidative half-reaction show a hyperbolic dependence on O2 concentration (in contrast to the other variants) with kox/Kd(ox) and kox values of 689 ± 92 mM−1s−1 and 156 ± 12 s−1 respectively, estimated from fit to equation (5). Means and standard deviations estimated from the fits to equations (3), (4) and (5). All kinetics were measured by triplicates.