Inosine 5 triphosphate

All salts were purchased from Sigma-Aldrich. Cytidine 5′-triphosphate (CTP; purity 95%); UTP (purity 90%); and guanidine 5′-triphosphate (GTP; purity 90%), used for single-channel experiments, were obtained from Acros Organics (Thermo Fisher Scientific). Inosine 5′-triphosphate (ITP; purity 98%), 6-chloropurineriboside-5′-triphosphate (6-Cl−rTP; purity 90%), 2′-fluoro-2′-deoxyadenosine-5′-triphosphate (C2′-F-dATP; purity 95%), 3′-deoxyadenosine-5′-triphosphate (C3′-dATP; purity 90%), and 2′,3′-dideoxyadenosine-5′-triphosphate (C2′-C3′-ddATP; purity 95%) were purchased from TriLink Biotechnologies. Adenosine 5′-triphosphate (ATP; purity 99%), GTP, used for two-electrode voltage clamp experiments (purity 95%), and 2′-deoxyadenosine-5′-triphosphate (C2′-dATP; purity 98%) were from Sigma-Aldrich. isoGTP (purity 93–95%) was purchased from Chemgenes, while Ara-Adenosine 5′-triphosphate (Ara-ATP; purity 96%) was from IBA Lifesciences. Last, locked nucleic acid–ATP (LNA-ATP) and unlocked nucleic acid–ATP (UNA-ATP) were provided by J. Wengel (University of Southern Denmark, Odense, DK).