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. 2010 Nov 19;404(1):56–69. doi: 10.1016/j.jmb.2010.08.008

Table 1.

Steady-state kinetic parameters of wild-type and E192X variants with Neu5Ac and DPAH

Enzyme Neu5Ac
DPAH
kcat (min− 1) Km (mM) kcat/Km (min− 1 mM− 1) kcat (min− 1) Km (mM) kcat/Km (min− 1 mM− 1)
Wild type 260 ± 6a 4.4 ± 0.3a 59a 73 ± 4a 11 ± 2a 7a
E192N 170 ± 10a 38 ± 5a 4.4a 130 ± 3a 0.4 ± 0.04a 340a
E192Q 300 ± 20 3.5 ± 0.5 85 170 ± 4 0.7 ± 0.05 250
E192V 120 ± 8a 34 ± 5a 3.5 95 ± 4a 0.4 ± 0.1a 270a
E192F 160 ± 5 5.9 ± 0.4 27 88 ± 2 0.3 ± 0.02 310
E192H 120 ± 5 6.2 ± 0.7 19 38 ± 1.0 0.5 ± 0.04 80
E192M 70 ± 4 5 ± 0.8 14 70 ± 3 0.2 ± 0.03 320
E192P 25 ± 1 6 ± 0.9 4 49 ± 1 0.2 ± 0.02 260
E192D 120 ± 5 4.6 ± 0.5 26 6 ± 0.1 1.1 ± 0.05 5
E192S 50 ± 3 6 ± 0.8 8 26 ± 0.7 0.6 ± 0.04 42

The steady-state kinetic parameters of the wild-type and variant enzymes for Neu5Ac and DPAH cleavage were measured with a standard coupled enzyme assay. Kinetic parameters (± standard error of the fit) were determined by fitting the data to the Michaelis–Menten equation.

a

Data taken from Williams et al.1