Figure 2.

Phosphate and 3-PGA protection from thermal inactivation. Desalted enzymes containing 0.5 mg/mL BSA were heated at 42°C for 10 min in the presence of varying concentrations of Pi (▪) or 3-PGA (▴). Duplicate samples were left on ice and their activity was taken to be 100%. All preparations were assayed for 10 min in the forward direction in the presence of 10 mm 3-PGA. The percentage of activity remaining was then calculated by dividing the heated versus nonheated samples and plotted against the effector concentration.