Human red-cell acid phosphatase (ACP1): kinetic and thermodynamic characterization of the KUK variant.

The Km constant and the sensitivity to inhibitors were determined for the rare variant KUK of red cell acid phosphatase. At the same time, the thermodynamic energies of activation and of inactivation were measured. The kinetic parameters were not very different from those of the usual ACP1 C alloenzymes. However, they differed in their thermodynamic energies: the conformational structure of the ACP1 KUK protein being less stable.