Valacyclovir and Acyclovir Are Substrates of the Guanine Deaminase Cytosolic PSD-95 Interactor (Cypin).

Valacyclovir, enzymatically hydrolyzed in the body to acyclovir, is a guanine-based nucleoside analog commonly prescribed as an antiviral therapy. Previous reports suggest that guanosine analogs bind to guanine deaminase; however, it is unclear whether they act as inhibitors or substrates. Data from our laboratory suggest that inhibition of guanine deaminase by small molecules attenuates spinal cord injury-induced neuropathic pain.