Conformations et spectre Raman de l'acide ribonucléique de transfert, tRNA

The structure of yeast tRNA^Asp in aqueous solution has been studied in sight of Raman spectra recorded between 5 and 82°C. A conformational change is evidenced at 20°C and an endomelting is found around 70°C. This melting temperature, much higher than in tRNA-^Phe (near 50°C) is interpreted by the presence of a higher number of G-C bases in tRNA^Asp.At a same temperature, the Raman spectrum of a tRNA^Asp 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.