FIGURE 6.

Model representing the reaction catalyzed by asparagine synthetase, comprising metabolites (circles), and reactions (squares). The concentration of metabolites is indicated abstractly by numbers in the circles. The model features 11 molecules: AMP, ATP, asparagine (Asn), glutamine (Gln), glutamate (Glu), aspartate (Asp), asparagine synthetase enzyme (ASNe), ASNe complexed with glutamine (ASNe–Gln), ASNe complexed with ammonia (ASNe–NH₃), β-aspartyl-complex (βAsp–AMP–ASNe–NH₃), and magnesium ions. Note that for clarity, water and pyrophosphate are not included. The model was generated assuming that the reactions follow mass action kinetics. The dissociation step for the ASNe–NH3 complex is highlighted in red.