The Bifunctional Pyruvate Decarboxylase/Pyruvate Ferredoxin Oxidoreductase from Thermococcus guaymasensis

Table 3

Kinetic parameters of POR and PDC of T. guaymasensis and P. furiosus.

Source	activity	Pyruvate^a		CoA^b		Specific; activity^c
		Apparent  𝐾𝑚 (mM)	Apparent  𝑉max (U mg^−1)	Apparent  𝐾𝑚 (μM)	Apparent   𝑉max (U mg^−1)
T. guaymasensis	POR	0.53±0.03	18±0.23	70±10	21.8±0.8	20.2±1.8
	PDC	0.25±0.05	3.8±0.14	20±1	3.3±0.09	3.8±0.22
P. furiosus	POR^d	0.46	23.6	110	39.9	22.0
	PDC^e	1.1	4.3±0.3	110	4.3±0.3	4.3±0.3

aFor POR measured at 0.1 mM CoA, 1 mM MV, 0.4 mM TPP, and for PDC at 1 mM CoA, 0.1 mM TPP.
^bFor POR measured at 5 mM pyruvate, 1 mM MV, and 0.4 mM TPP, and for PDC at 10 mM pyruvate and 0.1 Mm TPP.
^cExpressed as 𝜇moles of pyruvate oxidized⁻¹ mg⁻¹ of enzyme.
^dValues reported by Blamey and Adams (1993) [28] measured using EPPS (50 mM, pH 8.4) at 80°C.
^eValues reported by Ma et al. (1997) [6] measured using CAPS (50 mM, pH 10.2) at 80°C.