Km values
enzyme substrate Km (mM)
catalase H2O2 25
hexokinase (brain) ATP 0.4
D-Glucose 0.05
D-Fructose 1.5
carbonic anhydrase HCO3- 9
chymotrypsin glycyltyrosinylglycine 108
N-benzoyltyrosinamide 2.5
b-galactosidase D-lactose 4.0
threonine dehydratase L-Thr 5.0
kcat values
enzyme substrate kcat (s-1)
catalase H2O2 40,000,000
carbonic anhydrase HCO3- 400,000
acetylcholinesterase acetylcholine 140,000
b-lactamase benzylpenicillin 2,000
fumarase fumarate 800
RecA protein (ATPase) ATP 0.4