TABLE 7.

Isotope effects for the E78A, E122A, and E78A/E122A mutant enzymes

Parameter	Wild type SDH	E78A	E122A	E78A/E122A
D(V)	1.50 ± 0.07	(pH 5) 0.9 ± 0.1	2.1 ± 0.1	2.24 ± 0.10
		(pH 9) 1.13 ± 0.03
D(V/KLys)	1.60 ± 0.05	(pH 5) 1.9 ± 0.1	1.5 ± 0.1	2.24 ± 0.10
		(pH 9) 1.13 ± 0.03
D2O(V)	2.2 ± 0.1	(pH 9) 1.43 ± 0.05	1.8 ± 0.1	2.40 ± 0.05
D2O(V/KLys)	1.9 ± 0.1	(pH 9) 1.43 ± 0.05	2.6 ± 0.2	2.40 ± 0.05
D2O(V)D	1.76 ± 0.08 (80% D2O)	(pH 5) 2.90 ± 0.02	2.10 ± 0.04	3.6 ± 0.1
		(pH 9) 1.20 ± 0.01
D2O(V/KLys)D	1.86 ± 0.08 (80% D2O)	(pH 5) 2.90 ± 0.02	2.50 ± 0.08	3.6 ± 0.1
		(pH 9) 1.20 ± 0.01