TABLE 3.

Kinetic parameters for E78A, E122A, and E78A/E122A mutant enzymes in the direction of saccharopine formation at 25 °C and pH 7.2

Kinetic parameters at pH 7.2	SDH-WT	E78A	E122A	E78A/E122A
V2/Et (s−1)	20.0 ± 1.0	88.8 ± 4.7	19.4 ± 0.8	24.80 ± 0.04
Fold change		+4.4	∼1	+1.2
V2/KNADHEt (m−1s−1)	(1.6 ± 0.2) × 106	(2.5 ± 0.1) × 106	(3.1 ± 0.1) × 105	(2.20 ± 0.03) × 105
Fold change		+1.53	−5.1	−7.3
V2/KLysEt (m−1s−1)	(2.5 ± 0.4) × 104	(1.43 ± 0.08) × 105	(5.3 ± 0.2) × 102	(1.300 ± 0.002) × 102
Fold change		+5.7	−47	−192
V2/Kα-KgEt (m−1s−1)	(2.8 ± 0.7) × 105	(4.9 ± 0.4) × 105	(3.5 ± 0.2) × 104	(5.11 ± 0.01) × 103
Fold change		+1.8	−8	−55
KNADH (mm)	0.019 ± 0.002	0.036 ± 0.003	0.062 ± 0.034	0.113 ± 0.001
Fold change		+1.9	+3.3	+5.9
KLys (mm)	1.1 ± 0.2	0.62 ± 0.01	36.5 ± 1.1	190.7 ± 1.4
Fold change		−1.76	+33.0	+176
Kα-Kg (mm)	0.11 ± 0.03	0.180 ± 0.002	0.556 ± 0.004	4.850 ± 0.001
Fold change		+1.6	+5.1	+44.1
KiNADH (mm)	0.017 ± 0.003	0.038 ± 0.001	0.019 ± 0.003	0.015 ± 0.002
Fold change		+2.2	N/Aa	N/A

^a N/A, not applicable.