The activity of thiamine pyrophosphokinase (EC 2.7.6.2) has been demonstrated in the extract from human leukocytes using radiometric assay method. It was estimated to be 17.2 +/- 6.6 p moles of thiamine pyrophosphate formed per mg protein per hour at 37 degrees C. No thiamine pyrophosphokinase activity was detected in hemolysate of human erythrocytes under the assay condition employed.
