Notes: Guanosine 5'-diphosphate (GDP) is a purine nucleotide and biosynthetic precursor of guanosine 5'-triphosphate (GTP; Item No. 16060).{54328} It has been used to study the conformations of GTPases.{62261} GDP (100 µM) activates sulfonylurea receptor 2B (SUR2B) linked to the inward-rectifier potassium channel 6.1 (Kir6.1) in HEK293T cells in a patch-clamp assay.{62262}