. Author manuscript; available in PMC: 2012 May 18.

Published in final edited form as: J Am Chem Soc. 2011 Apr 21;133(19):7461–7468. doi: 10.1021/ja200277d

Table 2.

Steady-state kinetics of RPA1163 and mutants

	Fluoroacetate				Chloroacetate

Enzyme	k_cat (min⁻¹)	%	K_m (mM)	k_cat/K_m (s⁻¹M⁻¹)	k_cat (min⁻¹)	%	K_m (mM)	k_cat/K_m (s⁻¹M⁻¹)
WT^*	6.7 ± 0.6	100	3.3 ± 0.2	33	1.38 ± 0.07	21	1.6 ± 0.5	14
Phe40Ala	0.21 ± 0.04	3.1	4.4 ± 0.8	0.79	0.029 ± 0.009	0.44	1.5 ± 0.4	0.32
His155Asn	0.70 ± 0.06	11	2.9 ± 0.2	4.1	5.3 ± 0.5	79	2.0 ± 0.3	45
Trp156His	0.11 ± 0.01	1.7	8 ± 3	0.22	0.10 ± 0.02	1.5	6 ± 1	0.27
Trp185Phe	0.59 ± 0.04	8.8	3.3 ± 0.6	2.9	0.32 ± 0.04	4.7	1.0 ± 0.3	5.0
Tyr219Phe	0.035 ± 0.009	0.53	1.7 ± 0.2	0.34	0.42 ± 0.04	6.3	1.00 ± 0.07	7.0

The parameters were determined from at least triplicate measurements and the standard deviations are shown. The % activity normalizes all k_cat to FAc hydrolysis by WT.

Data reported previously.³⁰