APPLICATIONS OF LASER-RAMAN SPECTROSCOPY TO THE ANALYSIS OF POLYNUCLEOTIDES CONTAINING URIDINE RESIDUES

Qualitative characterization of uridine C(2')-endo-anti and C(3')-endo-anti forms has been carried out for the first time using Laser-Raman spectroscopy. Spectra are presented for some crystals containing the uridine residue whose conformations are known from their X-ray crystallographic analyses. Crystalline uridine and uridine 5'-monophosphate as its lithium, sodium, potassium, barium and cadmium salts give Raman bands in the 600-700 cm-1 range that seem to reflect sensitively and regularly the conformation of the uridine residue and, therefore, are proposed as convenient indicators of the above structures. A method for the determination of the uridine C(2')-endo-anti form in polyribonucleotides is also described. The usefulness of these characterizations in the conformational analysis of polyribonucleotides is shown.