Helical α-aminoisobutyric acid (Aib) foldamers show great potential as devices for the communication of conformational information across phospholipid bilayers, but determining their conformation in bilayers remains a challenge. In the present study, Raman, Raman optical activity (ROA), infrared (IR) and vibrational circular dichroism (VCD) spectroscopies have been used to analyze the conformational preferences of Aib foldamers in solution and when interacting with bilayers. A 310 -helix marker band at 1665-1668 cm-1 in Raman spectra was used to show that net helical content increased strongly with oligomer length. ROA and VCD spectra of chiral Aib foldamers provided the chiroptical signature for both left- and right-handed 310 -helices in organic solvents, with VCD establishing that foldamer screw-sense was preserved when the foldamers became embedded within bilayers. However, the population distribution between different secondary structures was perturbed by the chiral phospholipid. These studies indicate that ROA and VCD spectroscopies are valuable tools for the study of biomimetic structures, such as artificial signal transduction molecules, in phospholipid bilayers.

Faculty of Life Sciences University of Bradford Bradford West Yorkshire BD7 1DP UK

Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 16610 Prague 6 Czech Republic

Manchester Institute of Biotechnology University of Manchester 131 Princess St Manchester M1 7DN UK

School of Chemistry University of Bristol Cantock's Close Bristol BS8 1TS UK

School of Chemistry University of Manchester Oxford Road Manchester M13 9PL UK

School of Science RMIT University GPO Box 2476 Melbourne Victoria 3001 Australia

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