EVIDENCE FOR AN INTERACTION BETWEEN CYTOSOLIC ALDOLASE AND THE ATP-DEPENDENT AND PYROPHOSPHATE-DEPENDENT PHOSPHOFRUCTOKINASES IN CARROT STORAGE ROOTS

Immunoaffinity chromatography was employed to identify potential plant cytosolic aldolase (ALD(c)) binding proteins. A clarified homogenate of carrot storage root was chromatographed on a column of protein-A-Sepharose that had been covalently coupled to anti-(carrot root ALD(c)) immunoglobulin G. The column was washed with phosphate-buffered saline (PBS), followed by step-wise elution with increasing concentrations of NaCl in PBS. Several proteins were eluted following application of the salt gradient. Western blotting identified the major eluting proteins to be the PP(i)-dependent phosphofructokinase (PFP) and the cytosolic form of the ATP-dependent phosphofructokinase (PFK(c)), enzymes that are metabolically sequential to ALD(c). The results suggest that ALD(c) may specifically interact with PFP and PFK(c) in carrots.