Size-dependent ultrafast structural dynamics inside phospholipid vesicle bilayers measured with 2D IR vibrational echoes

作者：Kel Oksana; Tamimi Amr; Fayer Michael D^*

来源：Proceedings of the National Academy of Sciences, 2014, 111(3): 918-923.

DOI：10.1073/pnas.1323110111

• vesicle bilayer dynamics
• vesicle size dependent dynamics
• vesicles chainlength dependent dynamics

The ultrafast structural dynamics inside the bilayers of dilauroylphosphatidylcholine (DLPC) and dipalmitoylphosphatidylcholine vesicles with 70, 90, and 125 nm diameters were directly measured with 2D IR vibrational echo spectroscopy. The antisymmetric CO stretch of tungsten hexacarbonyl was used as a vibrational probe and provided information on spectral diffusion (structural dynamics) in the alkyl region of the bilayers. Although the CO stretch absorption spectra remain the same, the interior structural dynamics become faster as the size of the vesicles decrease, with the size dependence greater for dipalmitoylphosphatidylcholine than for DLPC. As DLPC vesicles become larger, the interior dynamics approach those of the planar bilayer.

• 出版日期2014-1-21