Interaction of bundled Ser-rich amphiphilic peptides with phospholipid membranes

✍ Scribed by Kazutoshi Yoshida; Naoya Ohmori; Yasuhiro Mukai; Takuro Niidome; Tomomitsu Hatakeyama; Haruhiko Aoyagi

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 127 KB
• Volume: 5
• Category: Article
• ISSN: 1075-2617
• DOI: 10.1002/(sici)1099-1387(199908)5:8<360::aid-psc208>3.0.co;2-q

✦ Synopsis

To investigate properties of hydrophilic bundled peptides and their interactions with phospholipid membranes, bundled peptides named [Trp 2 ]-and [Trp 12 ]-4h-4 6 S9, which are composed of four fragments of amphiphilic 24-mer peptide, were designed and synthesized. Tryptophan (Trp) was introduced at the 2nd position from the N-terminal or at the centre (12th) of the helix to monitor the peptide -lipid interaction. Circular dichroism measurements indicated that the peptides had low h-helicities in a buffer solution (pH 7.4) and also in the presence of dipalmitoyl-DL-3-phosphatidylcholine (DPPC) vesicles. In the presence of DPPC/dipalmitoyl-DL-3-phosphatidylglycerol (DPPG) (3:1) vesicles, the measurement could not be taken because of turbidity induced by vesicle aggregation. Both peptides had moderate perturbation activity for both the neutral and acidic vesicles at 25°C. The perturbation patterns at 50°C were much different from those at 25°C and the maximum activity reached 100% at a low peptide concentration. The results of the measurement of membrane fusion activity of peptides showed a similar tendency to that found in the perturbation experiment. A quenching experiment indicated that the Trp 2 and Trp 12 residues in [Trp 2 ]-and [Trp 12 ]-4h-4 6 S9 were scarcely embedded in neutral lipid membranes.