TABLE 1.

Kinetic parameters of purified enzymes involved in anaerobic oxidative degradation of l-ornithine

Enzyme	Substrate	Michaelian parameter			Non-Michaelian parametere
		Km (μM)	kcat (s−1)	kcat/Km (s−1·M−1)	S50 (μM)	Vmax (s−1)	n
DAPDH	NAD+a	16 ± 1	34 ± 0.7	2.1 106
	NADP+a	2,560 ± 280	5 ± 0.5	2.0 103
	(2R,4S)-DAPb				109 ± 4	51.6 ± 0.6	1.24 ± 0.04
	(2R,4R)-DAPb				1,800 ± 200	2.8 ± 0.1	1.77 ± 0.25
OR	l-Ornithine	520 ± 20	1,660 ± 30	3.2 106
AKPT	CoA-SHc	18 ± 3	3.5 ± 0.2	1.9 105
	AKPd	35 ± 6	3.4 ± 0.2	9.7 104

^aThe (2R,4S)-DAP concentration was 800 μM.

^bThe NAD⁺ concentration was 2 mM.

^cThe AKP concentration was 350 μM.

^dThe CoA-SH concentration was 80 μM.

^eS₅₀ is the substrate concentration showing half-maximal velocity, n is the Hill coefficient, and V_max is the maximal velocity.