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. Author manuscript; available in PMC: 2013 Mar 15.
Published in final edited form as: Arch Biochem Biophys. 2011 Oct 7;519(2):112–117. doi: 10.1016/j.abb.2011.10.003

Table 2.

Relative effects of residue substitutions on kinetic parameters and binding sites for NAD+ and AMP.

Enzyme Relative Vmax appa S0.5NAD+
(mM)		 NAD+
binding sites		 AMP
binding sites
IDH1/IDH2 1 0.2 2 2
IDH1/IDH2H281A 0.900 6.1 0 2
IDH1/IDH2D286A,I287A 0.006 8.2 NDb NDb
IDH1R274A/IDH2 0.500 0.8 2 0
IDH1D279A,I280A/IDH2 0.500 0.2 2 0
a

Kinetic Vmax app values were determined with respect to concentrations of NAD+. The Vmax app value measured for the wild-type enzyme (IDH1/IDH2) was ~38 units/mg [24].

b

ND = not determined. The IDH1/IDH2D286A,I287A enzyme was refractive to purification in amounts needed for ligand binding assays.