The Effect of Molybdate on the Activity of Tomato Acid Phosphat Ases

Abstract

The effectiveness of sodium molybdate as an inhibitor of tomato acid phosphatases was examined. Significant inhibition of cell-free dialysed extracts was obtained with as low as 1O-7M sodium molybdate. A range of substrates, including a number of glycolytic intermediates, was tested and all except glucose I-phosphate were hydrolysed by tomato leaf phosphatase preparations. Hydrolysis was always inhibited by molybdate. The inhibition was competitive; Ki= IO-5M.