Ultraviolet resonance Raman bands of guanosine and adenosine residues useful for the determination of nucleic acid conformation

Abstract

Abstract The ultraviolet resonance Raman (UVRR) bands of several guanine‐ and adenine‐containing mononucleotides were measured, and were compared with the classical and UVRR spectra of 9‐ethylguanine, which contains no furanose ring, in order to assess the effect of sugar conformation on the UVRR spectrum. For several guanine mononucleotides containing different furanose rings some differences were found in the Raman bands normally attributed to the purine vibrations. A similar effect exists with different adenosine mononucleotides. The fact that these vibrations are allowed in the rigorous resonance Raman effect indicates that they are coupled to the electronic transitions of the base. Differences which are seen between cyclic nucleotides, ribonucleotides and deoxyribonucleotides probably arise from differences in the conformation of the attached furanose rings. This provides a method for the identification of conformationally sensitive vibrations of purine rings in nucleic acids.