Biochemistry 4th Edition by Christopher Mathews,Kensal van Holde, Dean Appling, Spencer Anthony Cahill

Exercise 6

Upon activation by a receptor, a G protein exchanges bound GDP for GTP, rather than phosphor ylating GDP that is already bound. Similarly, the subunit-GTP complex has a slow GTPase activity that hydrolyzes bound GTP, rather than exchanging it for GDP. Describe experimental evidence that would be consistent with these conclusions.