Figure 9.

Combined effects of l-serine and activator amino acids. (a) Specific activities at various concentrations of l-serine were measured in the presence of each activator and are shown relative to those in the absence of l-serine. Half maximal effective concentrations (EC₅₀) of l-serine and Hill coefficients are summarized in tables. (b) Specific activities at various concentrations of activator amino acids in the presence of 20 mM l-serine are presented relative to those in the absence of activators. Data are presented as means and standard errors of three technical replicates (n = 3). Half maximal effective concentrations (EC₅₀) of effector amino acids and Hill coefficients are summarized in the table.