THE WHEAT LEAF PHOSPHATASES: VIII. A PREPARATION WITH PHOSPHOTRANSFERASE ACTIVITY

The nucleoside phosphotransferase of wheat leaves has been separated from the acid β-glycerophosphatase (EC 3.1.3.2) by chromatography on the weak base anion exchange resin Rexyn 203. The preparation is contaminated with 3′-nucleotidase (EC 3.1.3.6), acid pyrophosphatase (EC 3.6.1.1), and a phosphotransferase that apparently catalyzes the interconversion of adenosine 3′-phosphate and adenosine 5′-phosphate. The low level of acid β-glycerophosphatase activity in these preparations proves the existence of an active acid pyrophosphatase in wheat leaves that is distinct from classical acid phosphomonoesterase, which is supposed to hydrolyze pyrophosphate.