TABLE 2.

Kinetic parameters for the cleavage of the fluorogenic substrate (5 μm) by wild type catBoNT/A catalytic domain, C134S mutant, and C165S mutant (20 nm)

The assays were carried out in 40 mm Hepes, pH 7.4, at 37 °C.

Enzyme	Km	kcat	kcat/Km
	10−6 m	s−1	m−1·s−1
Wild type	68 ± 13	0,54 ± 0,07	7948
C134S	85 ± 11	0,54 ± 0,05	6430
C165S	76 ± 15	0,014 ± 0,001	190
C134S/C165S	35 ± 7	0,007 ± 0,008	220