Skip to main content
. Author manuscript; available in PMC: 2008 Oct 23.
Published in final edited form as: Biochemistry. 2007 Sep 29;46(42):11780–11788. doi: 10.1021/bi701408t

Table 5.

Comparison of Michaelis Constants and Equilibrium Binding Constants for ATP to Wild-Type and Mutant PMKs. a

Enzyme Km(ATP) (μM) Fold Inflation Kd(ATP) (μM) c Fold Inflation
WT 107±14 - 30±3 -
R141M 5200±474b 49 816±160 27
a

Spectrophotometric assays were performed in 100 mM MOPS, 200 mM KCl, 1 mM DTT (pH 7.0) in the presence of 10 mM MgCl2 at 30°C. [ATP] was kept saturating (5 mM). Errors represent the standard error of the fit.

b

Assays contained 20 mM MgCl2.

c

Determined by tryptophan fluorescence. Averaged data points from 3 [protein] were fit to a two site model using the equation y = Bmax1[X]/(Kd1 + [X]) + Bmax2[X]/(Kd2 + [X]).

d

Kd2 values (WT: 14 mM, R141M: 41 mM) are too weak to be physiologically relevant and are not considered in the comparison. Errors represent the standard error of the fit.