I am in intro to Biochem and my professor gave me this problem for extra credit, and I have no idea how to answer it. Any insite would be great. Thank you.

Your patient has a benign tumor of his Schwann cells. He also has an altered protein. You do an experiment in which you incubate the protein p21ras with this protein and measure what percentage of the guanine nucleotide bound to the p21ras is GTP.

Results:
Protein……………………………………..GTP/(GTP+GDP) on p21ras (%)
Your patient’s protein…………………………………………50
Normal protein………………………………………………….5

Questions:
a. What is the role of the protein that appears to be defective in your patient? How could the mutation cause the observed problem?

b. Why might an inhibitor of farnesylatransferase help this disease?