Enzyme Relational Network Reveals Target Enzymes within Metabolic Submodules

Identification of enzyme targets for metabolic engineering requires a global view of the functional relationship among enzymes within metabolic network. In this paper, we propose a method to construct an enzyme relational network based on the significant effect of the rate change of one reaction on the rate of another reaction. We illustrate the method by using a kinetic model to formulate the enzyme relational network of the sucrose-to-starch conversion process. The network obtained shows two separate submodules, one of which possesses the enzymes located in cytosol; the other, in amyloplast. The network reveals that ADP-glucose pyrophosphorylase and inorganic pyrophosphatase are potential target enzymes for metabolic engineering to improve starch yield.