SOLUTION CONFORMATION OF N-TERMINAL FRAGMENTS OF TRICHOSANTHIN SMALL DOMAIN (TCS-182-200) - CIRCULAR DICHROIC STUDIES

Three peptides, T14, T18 and TDK, derived from the N-terminus of trich osanthin small domain (TCS 182-200) have been investigated by circular dichroism. Secondary structure and structural transitions of the abov e peptides under different conditions were studied. Alcohol prompts a transition of the T18 peptide from a beta-sheet to an alpha-helical st ructure. It also increases the alpha-helicities of T14 and TDK. The be ta-sheet of T18 peptide appears more hydrophobic than the alpha-helix of T14 or TDK. The effects of polypeptide sequence and solvent on seco ndary structure formation of these model peptides are discussed. (C) M unksgaard 1997.