FIGURE 2.
The two-site scheme used in analyzing the present enzyme kinetic data. (A) In the absence of an activator, the substrate binds at two sites, the active site and an activator/effector site. (B) In the presence of an activator, the short-chain phospholipid diC6PC, the activator binds only to the activator site and is able to displace the substrate from this site. These two schemes, separately and in combination, were fitted to the data. E, enzyme; S, substrate; A, activator; and P, reaction product.