P1,P4-Di(guanosine-5′) tetraphosphate (Diguanosine tetraphosphate) (GP4G) is a dinucleoside polyphosphate which may be used to study potential pathological effects of dinucleoside polyphosphtes in vivo. GP4G is an acceptor molecule for cytidine-3′, 5′-bisphosphate from the adenylylated donor 5′-adenylylated cytidine 5′,3′-bisphosphate in the T4 RNA ligase catalyzed reactions. GP4G is a used as an inhibitor of DNA apurinic/apyrimidinic endonuclease (APE1).
