Question: The enzyme phosphofructokinase (PFK) catalyzes a key step in the breakdown of glucose in the init…
Show transcribed image text the enzyme phosphofructokinase (PFK) catalyzes a key step in the breakdown of glucose in the initial steps of cellular respiration. PFK uses ATP to catalyze the following phosphorylation reaction: Fructose-6-phosphate + ATP + PFK rightarrow Fructose-1 -6-bisphosphate + ADP + PFK a. What two molecules would you expect to find in the active site of PFK during its catalytic function? Interestingly, ATP can also serve as a non-competitive (allosteric) inhibitor of PFK. b. Would you predict that this inhibition occurs through the same binding site you answered above, or perhaps an alternative site on the PFK enzyme? c. Briefly describe how ATP binding at this non-active site could be inhibiting PFK activity. d. Which ATP-binding site would you predict to have a higher affinity for ATP and why? e. Suppose you designed an inhibitor drug that selectively binds to the allosteric PFK site. Draw a graph with Michaelis curves you would predict for PFK in the absence and presence of this inhibitor.
the enzyme phosphofructokinase (PFK) catalyzes a key step in the breakdown of glucose in the initial steps of cellular respiration. PFK uses ATP to catalyze the following phosphorylation reaction: Fructose-6-phosphate + ATP + PFK rightarrow Fructose-1 -6-bisphosphate + ADP + PFK a. What two molecules would you expect to find in the active site of PFK during its catalytic function? Interestingly, ATP can also serve as a non-competitive (allosteric) inhibitor of PFK. b. Would you predict that this inhibition occurs through the same binding site you answered above, or perhaps an alternative site on the PFK enzyme? c. Briefly describe how ATP binding at this non-active site could be inhibiting PFK activity. d. Which ATP-binding site would you predict to have a higher affinity for ATP and why? e. Suppose you designed an inhibitor drug that selectively binds to the allosteric PFK site. Draw a graph with Michaelis curves you would predict for PFK in the absence and presence of this inhibitor.
