N-acyl-(alpha, gamma diaminobutyric acid)n hydrazide as an efficient gene transfer vector in mammalian cells in culture.
OBJECTIVE
This study investigates the structure/activity relationship of a series of N-acyl-peptides (lipopeptides) for the transfection of mammalian cells.


METHODS
Lipopeptides comprising 1 to 3 basic amino-acids and a single fatty acid chain were synthesized. Transfecting complexes between lipopeptide, plasmid DNA and dioleoyl phosphatidylethanolamine were prepared and applied on cells in culture. Transfection efficiency was evaluated by measuring beta-galactosidase activity 48 h post-transfection. Lipopeptide-DNA binding was also investigated by physical means and molecular modelling.


RESULTS
Besides the length of the fatty acid chain, the nature of the basic amino-acid and the C-terminal group were crucial parameters for high transfection efficiency. The N-acyl-(diaminobutyric acid)n derivatives were the most potent transfecting agents among those tested and induced a beta-galactosidase activity 2 to 20 times higher than the N-acyl-lysine, -ornithine or -diaminopropionic acid derivatives. Furthermore, a hydrazide C-terminal modification greatly enhanced transfection efficiency for all compounds tested. The reason why alpha, gamma-diaminobutyric acid hydrazide-based lipopeptides were the most potent in transfection is not fully understood but could be related to their high DNA binding.


CONCLUSIONS
Poly- or oligo-diaminobutyric acid containing or not a hydrazide C-terminus could advantageously be used in peptide-based gene delivery systems.
Legendre
J Y
JY
Pharma Division, F. Hoffmann-La Roche AG, Basel, Switzerland.
Trzeciak
A
A
Bur
D
D
Deuschle
U
U
Supersaxo
A
A
D000613:Aminobutyrates / Q000138:chemical synthesis* / Q000494:pharmacology; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D005347:Fibroblasts / Q000502:physiology; D018014:Gene Transfer Techniques; D005822:Genetic Vectors; D000882:Haplorhini; D006834:Hydrazines / Q000138:chemical synthesis* / Q000494:pharmacology; D007668:Kidney / Q000166:cytology; D008958:Models, Molecular; D010957:Plasmids; D014162:Transfection
D000613:Aminobutyrates; D006834:Hydrazines