Conformational properties of five peptides encompassing the entire sequence of pGSTP1-1 domain II

The conformation of five peptides encompassing the entire sequence of domai n II of pGSTP1-1 were examined in aqueous solution and at varying concentra tions of 2,2,2-trifluoroethanol (TFE). CD analysis of alpha4, alpha5, alpha 7 and alpha8 Fragments indicates that these peptides are predominantly unst ructured in water or in the presence of TFE. On the contrary, the synthesiz ed alpha6-peptide, in the presence of solvents less polar than water, shows the same helical conformation adopted by the corresponding alpha6-helix in the hydrophobic core of the protein. This is essentially due to a strictly conserved N-capping box motif, present at the beginning of alpha6-helix. T his region might represent a nucleation site of GST. (C) 2001 Elsevier Scie nce Ireland Ltd. All rights reserved.