MOLECULAR ASSEMBLING OF DNA WITH AMPHIPATHIC PEPTIDES

The self-assembling of double-stranded DNA with short synthetic peptid es has been analysed using the fluorescent properties of the intercala ting dye, ethidium bromide, Two membrane-active peptides with appropri ate sequences of lysine and leucine amino acids and a short polylysine have been probed, The results revealed that the secondary structure o f the peptide decisively aimed the peptide-DIVA complex formation: onl y the longest peptide, which is the only one to exhibit an cl-helical structure in solution, could achieve DNA compacting before charge neut ralisation, The obtained complex retained a significant membrane activ ity as demonstrated by calcein leakage experiments, This shows that sh ort synthetic peptides of elementary sequence can combine both membran e activity and DNA-condensing properties, The potential of these const ructs as DNA carriers will be discussed, (C) 1998 Federation of Europe an Biochemical Societies.