TRIFLUOROETHANOL INDUCES THE SELF-ASSOCIATION OF SPECIFIC AMPHIPATHICPEPTIDES

We have examined the effect of trifluoroethanol (TFE) on the solution behaviour of three amphipathic peptides, One of the peptides, containi ng three heptad repeat units (Ac-YS-(AKEAAKE)(3)GAR-NH2), remained mon omeric under conditions where TFE induced a two-state transition from a random coil to an alpha-helix, In contrast, the TEE-induced alpha-he lical formation of two peptides derived from human apolipoproteins CII and E was accompanied by the formation of discrete dimers and trimers , respectively, The apolipoprotein C-II peptide further aggregated to form beta-sheet at higher concentrations of TFE (50% v/v), The results suggest a class of peptides capable of discrete self-association in t he presence of cosolvents which favour intramolecular hydrogen bonding . (C) 1997 Federation of European Biochemical Societies.