Journal of the American Chemical Society, Vol.118, No.18, 4240-4248, 1996
The Structure and Energetics of Helix Formation by Short Templated Peptides in Aqueous-Solution .2. Characterization of the Helical Structure of AC-Hel(1)-ALA(6)-Oh
Analysis of NOE cross-peaks in H-1 NMR ROESY spectra of Ac-Hel(1)-Ala(6)-OH in water and in water-trifluoroethanol mixtures demonstrates that the template Ac-Hell initiates an alpha-helix in a linked hexa-Ala peptide. Other NMR parameters and circular dichroism spectra are consistent with the presence of an alpha-helix, frayed at the C-terminus. Effects of NaCl, urea, temperature, and trifluoroethanol on the stability of a short alanine helix are reported.
Keywords:COIL STABILITY-CONSTANTS;ALANINE-BASED PEPTIDES;OCCURRING AMINO-ACIDS;N-TERMINAL TEMPLATES;ALPHA-HELIX;SOLUTION CONFORMATION;SECONDARY STRUCTURE;CHEMICAL-SHIFTS;(2S;5S;8S;11S)-1-ACETYL-1;4-DIAZA-3-KETO-5-CARBOXY-10-THIATRICYCLO(2.8.1.04;8)-.;PROTEIN HELICES