. . . . . . . . . . "A non-hydrolyzable analog of GTP, in which the oxygen atom bridging the beta to the gamma phosphate is replaced by a nitrogen atom. It binds tightly to G-protein in the presence of Mg2+. The nucleotide is a potent stimulator of adenylate cyclase. [PubChem]"@en . . . . "Phosphoaminophosphonic Acid Guanylate Ester"@en . . . . . . . . . . . . . . . "experimental"@en . . . . . . .