[Conformation and Raman spectra of the transfer ribonucleic acid, tRNAAsp].

The structure of yeast tRNAasp in aqueous solution has been studied in sight of Raman spectra recorded between 5 and 82 degrees C. A conformational change is evidenced at 20 degrees C and an endomelting is found around 70 degrees C. This melting temperature, much higher than in tRNA-phe (near 50 degrees C) is interpreted by the presence of a higher number of G-C bases in t RNA asp. At a same temperature, the Raman spectrum of a tRNAasp crystal is quasi-identical than that of an aqueous solution, indicating a high structural similarity except bands corresponding to G, C bases which show a more effective stacking of these bases in the solid.