. 2014 Apr 10;53(18):2915–2925. doi: 10.1021/bi500246z

Table 1. Kinetic Parameters Determined for MtIPMS Variants^a.

enzyme	k_cat (s^–1)	K_AcCoA (μM)	k_cat/K_AcCoA (μM ^–1 s^–1)	K_KIV (μM)	k_cat/K_KIV (μM ^–1 s^–1)
WT	3.4 ± 0.3	42 ± 12	0.08 ± 0.02	6.4 ± 1.4	0.50 ± 0.13
L79A	1.0 ± 0.1	30 ± 5	0.03 ± 0.01	120 ± 30	0.008 ± 0.002
R80A/K	nd^b	nd	nd	nd	nd
D81A/H	nd	nd	nd	nd	nd
N83A	0.31 ± 0.04	990 ± 290	0.0003 ± 0.0001	51 ± 14^c	0.006 ± 0.002
N83E	nd	nd	nd	nd	nd
Q84A	0.10 ± 0.02	170 ± 60	0.0006 ± 0.0002	19 ± 6	0.005 ± 0.002

Determined using 4,4-dithiodipyridine (DTP) to detect the formation of CoA at 324 nm (ε = 19.8 mM^–1 cm^–1) at 25 °C. Standard reaction conditions consisted of 50 mM potassium phosphate buffer (pH 7.5), 12 mM MgCl₂, 50 μM DTP, and at least 5–10 times the K_m value for the nonvaried substrate (AcCoA or KIV).

Activity could not be determined above the detection limit of the assay.

Determined using 1 mM AcCoA.

Table 1. Kinetic Parameters Determined for MtIPMS Variantsa.

Table 1. Kinetic Parameters Determined for MtIPMS Variants^a.