M. Rueping, A. Dietrich, V. Buschmann
Aug 23, 2001
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0
Influential Citations
17
Citations
Journal
Macromolecules
Abstract
Oligomers of (R)-3-hydroxybutanoic acid (OHBs) consisting of 8, 16, and 32 HB units have been investigated by CD spectroscopy in solution and in a racemic phospholipid bilayer. A Freudenberg plot (ϑ/n vs (n − 2)/n) of the data obtained in solution can be interpreted as an indication for the presence of a chiral secondary structure of the oligoester chainon the very short time scale of UV spectroscopy! The OHBs were also combined with fluorescent groups, including donor/acceptor pairs (coumarin, rhodamine, cyanine, oxazine). This enabled their detection by fluorescent microscopy and fluorescence-resonance-energy-transfer (FRET) measurements. With these techniques it was possible to calculate the distance between the fluorescent groups, thus providing information about the conformation of the OHB chain. With a calculated Forster distance R0 of 60 A the distance (in 10-6 M CHCl3) between the termini of HB 8-, 16-, and 32-mer were calculated to be 41, 38, and 49 A, respectively. This result is compatible with...