Table 1.

Kinetic parameters of Vgb and mutants

Enzyme	Km, μM	kcat, s−1	kcat/Km, M−1·s−1
WT	14 ± 3	11 ± 1	7.8 × 105
Loop change	16 ± 3	11 ± 1	7.0 × 105
Y18F	60 ± 9	0.08 ± 0.01	1.3 × 103
H228A	n.a.	n.a.	n.a.
E268Q	21 ± 4	0.30 ± 0.02	1.4 × 104
H270A	n.a.	n.a.	n.a.
E284Q	20 ± 6	0.11 ± 0.01	5.7 × 103

n.a., not available.