Cyclic hexapeptides bearing carboxyl groups. Interaction with metal ions and lipid membrane.
Three cyclic hexapeptides bearing carboxyl groups, cyclo(L-Asp-L-Phe-L-Pro)2, cyclo(L-Aad-L-Phe-L-Pro)2 (Aad represents alpha-amino adipic acid residue), and cyclo(D-Asp-D-Phe-L-Pro)2 were synthesized and investigated on conformation, complexation with metal ions, and interaction with lipid membrane. These cyclic hexapeptides were found to take several different conformations, though their reference compounds, cyclo(L-Leu-L-Phe-L-Pro)2 and cyclo[D-Asp(OMe)-D-Phe-L-Pro]2, took a single C2 symmetric conformation. Cyclo(D-Asp-D-Phe-L-Pro)2 formed complexes with Ba2+ and Ca2+, whereas cyclo(L-Asp-L-Phe-L-Pro)2 and cyclo(L-Aad-L-Phe-L-Pro)2 did not. The latter two take amphiphilic structures and were distributed to lipid membrane more easily than cyclo(D-Asp-D-Phe-L-Pro)2. Cyclo(D-Asp-L-Phe-L-Pro)2 binds Ca2+ on the lipid membrane.
Ozeki
E
E
Department of Polymer Chemistry, Kyoto University, Japan.
Miyazu
T
T
Kimura
S
S
Imanishi
Y
Y
D015060:1,2-Dipalmitoylphosphatidylcholine; D000595:Amino Acid Sequence; D002118:Calcium; D007202:Indicators and Reagents; D008081:Liposomes; D009682:Magnetic Resonance Spectroscopy; D008962:Models, Theoretical; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000138:chemical synthesis*; D010456:Peptides, Cyclic / Q000138:chemical synthesis*; D013050:Spectrometry, Fluorescence
D007202:Indicators and Reagents; D008081:Liposomes; D009842:Oligopeptides; D010456:Peptides, Cyclic; D015060:1,2-Dipalmitoylphosphatidylcholine; D002118:Calcium