¹ Source: wiktionary.com
Medical Definition of GTP
1. An immediate precursor of guanine nucleotides in RNA; similar to ATP; has a crucial role in microtubule formation. GTP cyclohydrolase, an enzyme that catalyses the reaction of GTP and H2O forming formate and a precursor of tetrahydrobiopterin; a deficiency of this enzyme will result in one form of malignant hyperphenylalaninaemia. Acronym: GTP (05 Mar 2000)