Figure 2
Effect of proximity channeling in dilute and crowded systems. (a) Reaction velocities for channeling of glyceraldehyde 3-phosphate (g3p, intermediate) in the transketolase-transaldolase (TK-TAL) part of the pentose phosphate pathway. A competing enzyme was triose-phosphate isomerase (TPI), which is diffusion limited. (b) Reaction velocities for channeling of fructose 6-phosphate (f6p, intermediate) in the glucose-6-phosphat-isomerase and phosphofructokinase-1 (PGI-PFK1) part of the glycolysis. A competing enzyme was phosphofructokinase-2 (PFK2). All enzymes in (b) are activity limited. The diffusion coefficients of g3p and f6p were taken D = 0.6 nm2/ns in a dilute and D = 0.06 nm2/ns in a crowded system. Dash lines show the reaction velocities for the non-channeled systems. The concentration of enzyme and enzyme conjugates were 26 nM in all systems.
