. Author manuscript; available in PMC: 2022 Jun 2.

Published in final edited form as: J Am Chem Soc. 2021 May 20;143(21):8193–8207. doi: 10.1021/jacs.1c03572

Table 1.

Kinetic constants for the inactivation of hOAT and GABA-AT by 1, 5, 9, 10, and 12–15^a

Comp.	hOAT			GABA-AT
Comp.	K_I (mM)	k_inact (min⁻¹)	k_inact/K_I (mM⁻¹min⁻¹)	K_I (mM)	k_inact (min⁻¹)	k_inact/K_I (mM⁻¹min⁻¹)

12	1.3 ± 0.2	0.1 ± 0.007	0.08	1.3 ± 0.4	0.03 ± 0.002	0.02
13	1.5 ± 0.2	0.1 ± 0.005	0.07	> 13.1	>0.2	0.02 ± 0.001^b
14	0.01 ± 0.002	0.2 ± 0.01	20.0	> 1.2	> 0.4	0.3 ± 0.01^b
15	0.1 ± 0.01	0.05 ± 0.002	0.5	> 2.5	> 0.2	0.09 ± 0.003 ^b
5 ²⁹	0.12	0.1	0.8	0.06	2.1	34.9
9 ²⁹	0.003	0.03	7.6	0.01	3.3	342
10 ⁴⁰	0.07	0.06	0.9	-	-	-
1 ⁴⁰	-	-	-	0.3	0.2	0.7

k_inact and K_I values were determined by the equation: k_obs = k_inact*[I]/(K_I +[I]) and are presented as means and standard errors.

The ratio of k_inact/K_I was determined by the slope of k_obs = k_inact*[I]/(K_I +[I]). k_inact is greater than the maximum k_obs determined in the time-dependent assay; K_I is greater than k_obs(max)/the ratio of k_inact/K_I.