Fig. 2: Kinetics analysis of 2 fructokinase isoform proteins from E. coli expressing MdFRKs.

a Schematic gene structure of pSUMO-M/MdFRK1 and pSUMO-M/MdFRK2 constructs. b SDS-PAGE and western blot results. For MdFRK1 (left): Lanes M1, M2, protein markers; 1, MdFRK1 (2.00 μg); 2, BSA (2.00 μg); 3, FRK1 (His antibody). For MdFRK2 (right): Lanes M1, M2, protein markers; 1, MdFRK2 (2.00 μg); 2, BSA (2.00 μg); 3, FRK2 (His antibody). c Effect of fructose concentration on MdFRK1 (left) and MdFRK2 (right) activity in extracts prepared from E. coli. Inset shows the level at which fructokinase activity inhibition begins