The relative change in the flux through the metabolic system can be related to the relative change in enzyme activity through the global control coefficient:
. (A.1)
Rearranging this equation leads to Eq. 22 in the paper:
, (22)
Similarly
(A.2)
leads to Eq. 23:
. (23)
Because the flux leads through enzyme 6,
. (A.3)
Rearranging this equation leads to Eq. 24 in the paper:
, (24)
Similarly
(A.4)
leads to Eq. 25 in the paper:
. (25)
For the system with two variable enzymes the expressions for the global control coefficients are identical. The expressions for the intra-modular control coefficients include an extra term accounting for the change in the enzyme of reaction 5:
. (A.5)
Using the summation theorem for flux control this equation can be written as:
. (A.6)
which rearranges to Eq. 27 in the paper.
, (27)
Doing the same for the concentration of the metabolite
, (A.7)
, (A.8)
leads to Eq. 28:
. (28)