Table II.

Kinetic analysis of ADK1 and 2

Adenosine KinaseSubstrateKmVmaxVmax/Km
μm μmol min−1mg−1 protein L min−1 mg−1protein
ADK1Adenosine0.502.75.4
ATP3503.50.010
Isopentyladenosine3.20.0680.021
ADK2Adenosine0.306.722
ATP3707.80.021
Isopentyladenosine4.80.660.14

Purified recombinant ADK1 and 2 were used to determine bothK m and V max for three substrates of adenosine kinase.V max/K m is presented here as a measure of overall enzyme efficiency for each substrate. Assays were as described in “Materials and Methods.”