 GTPgammaS

GTPgammaS (GTPγS, guanosine 5'-O-[gamma-thio]triphosphate) is a non-hydrolyzable or slowly hydrolyzable G-protein-activating analog of guanosine triphosphate (GTP).Many GTP binding proteins demonstrate activity when bound to GTP, and are inactivated via the hydrolysis of the phosphodiester bond that links the γ-phosphate to the remainder of the nucleotide, leaving a bound guanosine diphosphate (GDP) and releasing an inorganic phosphate.