A phosphorylating extract was prepared from commercial baker×s yeast with slight modification of the
procedure described in [9]. The yeast cells were dried at 28 for 24 h and then treated with 0.3 K-phosphate
buffer (pH 7.0; 10 ml/g of dry yeast) containing 15 m MgCl2 and 3% glucose. The suspension was kept for 3 h
at 28 and then centrifuged (8000 g, 5 min). The supernatant was used as the source of phosphorylating
enzymes.