Individual molecules of thermostable alkaline phosphatase support different catalytic rates at room temperature.

Thermus thermophilus cells were grown at 70 degrees C, lysed and the lysate subjected to single molecule alkaline phosphatase assays, using a capillary electrophoresis laser-induced fluorescence detection-based method. The enzyme was found to be heterogeneous with respect to catalytic rate when assayed at room temperature. Turnover numbers ranged 12-fold, with an average of 400 +/- 200 reactions/min for the 80 molecules assayed.