Theory 51/Metabolic Engineering
Flux Is a Capacity Ratio
The claim
Pathway flux is set by the ratio of enzyme capacity to pathway demand, so overexpressing one enzyme helps only until it stops being the limiting capacity.
01The mechanism
Flux through a chain is limited by the slowest step; raising capacity elsewhere has no effect until the bottleneck moves.
02Predictions
- P1Flux should track the limiting ratio.
- P2Total enzyme expression should mispredict.
03Refutation
Flux tracking total expression would remove the bottleneck.