1.D.13 The DNA-delivery Amphipathic Peptide Antibiotics (DAPA) Family
Histidine-containing synthetic amphipathic cationic peptides have been found to have dual activities. They (1) deliver DNA into various cell lines in the tissue culture environment, and (2) serve as antibiotics (Kichler et al., 2003). The α-helical conformation positions the positively charged residues on one face of the helix where they presumably interact with the DNA. Sequences of such peptides are provided by Kichler et al., 2003. One (LAH3) is: K K A L A L G L H L A H L A L H L A L A L K K A. The numbers of histidines, their positions in the sequence, and the pH at which the peptides change from an inplane to a transmembrane alignment are all critical.
The reaction catalyzed by DAPA family members is:
DNA (out) → DNA (in)