Guanosine diphosphate
Guanosine diphosphate, also known as GDP, Guanosine 5'-diphosphate and Guanosine pyrophosphate[1], is a nucleoside diphosphate and is an ester of pyrophosphoric acid combined with a nucleoside guanosine molecule. It is made up of a pyrophosphate group, a pentose sugar ribose and the base guanine[2].
GDP can be converted into GTP with the help of pyruvate kinase and phosphoenolpyruvate. GDP is also the product of GTP dephosphorylation by GTPases, e.g. theG-proteins that are involved in signal transduction[3].