Abstract
1. The time course of the incorporation of radioactive inorganic phosphate into 2, 3-diphosphoglycerate and ATP in steady-state glycolysis of red cells was studied.
2. The incorporation into diphosphoglycerate had always a distinct lag, whereas that into ATP showed no lag.
3. The specific activities of P32 in the 2 and 3 positions of diphosphoglycerate were the same for the incubation time from 5 to 40 minutes.
4. In acidic pH, the incorporation into diphosphoglycerate was low and increased with the increase of pH. The incorporation into ATP did not depend so much on pH.
5. The incorporation of radioactive inorganic phosphate into 2, 3-diphosphoglycerate may possibly be interpreted as due to the exchange reaction in the phosphoglyceromutase step, without considering the contribution of the diphosphoglycerate cycle.
The authors express their thanks to Miss N. Shinohara for her assistance and to Dr. T. Saito for his discussion. Thanks are also due to Dr. M. Miyamoto, the president of the Plasma Institute, Tokyo, for the generous supply of blood and to Hoansha Foundation for the financial aid.
