8-Azaguanosine

8-Azaguanosine is an azapurine nucleoside.An extensive study has been made of the fluorescence emission properties of the neutral and ionic forms in aqueous medium of the 8-Azaguanosine. The 8-?azaguanosine is a substrate of purine nucleoside phosphorylase (PNP)?.

8-Azaguanosine (azaG) could replace specifically guanosine in the GpUpU codon for valine or the GpCpU codon for alanine in the stimulation of the binding of [14C]aminoacyl-tRNA to ribosomes. However, the binding efficiency in the presence of azaG-containing triplets was lower than in the presence of the natural codons. AzaG could replace guanosine in the 5'-position of codons for valine, alanine, and aspartic acid, as well as in the second position of codons for arginine. However, the template activity of azaG-containing triplets is lower than that of "normal" codons[1].

[1] D. Grünberger, F. ?orm, A. Holy?. “Synthesis and coding properties of 8-azaguanosinecontaining triribonucleoside diphosphates.” Biochimica et Biophysica Acta-Bioenergetics 31 1 (1968): 147–55.