Figure 1.

Molecular modeling, amino acid sequence, and charge distribution of lipid-like self-assembling peptides. The peptide length is similar to biological phospholipids. The hydrophobic domain of the peptides consists of six alanines. Color code: cyan, carbon; red, oxygen; blue, nitrogen; white, hydrogen. Illustrations were generated by VMD. Highlighted domains represent amino acids with positive charge (blue), negative charge (red), and hydrophobic side chains (grey). Using pK_a values from the literature the net charge of the peptides at pH 7.4 was calculated to be ac-A₆K-CONH₂ (+1), KA₆-CONH₂ (+2), ac-A₆D-COOH (−2), DA₆-COOH (−1).