Guanosine diphosphate (GDP)
Molecular formula: C10H15N5O11P2
Guanosine diphosphate is a purine nucleoside diphosphate, and is a product of the dephosphorylation of guanosine triphosphate (GTP) by GTPases. The conversion of GTP to GDP (and vice versa) has a physiological involvment in G-Protein signal transduction, whereby the G-Protein exchanges it's bound GDP for GTP, leaving it in an active state. In order for the conversion GDP to GTP to take place, the enzymes pyruvate kinase and phosphoenolpyruvate are necessary.