CONFORMATION OF A PEPTIDE CORRESPONDING TO T4 LYSOZYME RESIDUES-59-81BY NMR AND CD SPECTROSCOPY

The conformation, in solution, of a peptide corresponding to residues 59-81 from T4 lysozyme [LYS(59-81)] has been determined by H-1 NMR and CD spectroscopy. This peptide spans the region corresponding to helix C in the crystal structure of T4 lysozyme. Secondary structure predic tions indicated that the peptide would possibly be helical in an aqueo us environment, but in a more hydrophobic environment the peptide woul d certainly adopt a helical conformation. This prediction was confirme d by the far-UV CD and NMR studies, which showed the peptide to be rel atively unstructured in aqueous solution and significantly helical in the presence of either TFE or SDS micelles, although the H-1 NMR resul ts did give some indication of the presence of nascent helix in aqueou s solution. For LYS(59-81), in TFE, the three-dimensional structure de rived from the NMR data showed that the helix had a more pronounced cu rvature than the gradual bend observed in the crystal structure.