Effect of nitrobenzene on the Raman spectra of ribonuclease in aqueous solution

The Raman spectra of the native ribonuclease treated with nitrobenzene in aqueous solution were obtained. The conformations of the main chain and the side chain in ribonuclease were studied. Among the amide I and amide III bands, the characters of beta -sheet and random coil structures are clear. The disulfide bridges assume the gauche-gauche-gauche conformation. The parts of tyrosine residue are buried. It indicates that the nitrobenzene treatment on protein aqueous solution is an efficient means for obtaining better Raman spectra.