The Isolation of Guanosine Tetraphosphate from Commercially Available Preparations of Guanosine Triphosphate.

The isolation of adenosine tetraphosphate and pentaphosphate from samples of adenosine triphosphate has been reported by Marrian (1) and Sacks (2). The available evidence is consistent with a st,ructure in which the phosphate residues are linked by phosphoanhydride bonds to one another and are carried by the 5’-hgdroxyl group of the ribose moiety (l-4). During attempts to estimate guanosine triphosphate by ion exchange thin layer chromatography (5), it was found that the samples of commercial guanosine triphosphate investigated contained a component that migrated more slowly than guanosine triphosphate, and const,ituted between 5 and 107, of the absorbance at 252 rnp. This paper is concerned with the purification and analysis of this component, which has proved to be guanosine tetraphosphate.