Bilayer thickness estimations with 'poor; diffraction data

摘要

The lamellar fluid phase (smectic A) is the biologically most relevant membrane structure and is extensively studied by x-ray (neutron) diffraction. However, either due to experimental limitations or due to lattice disorder bilayer diffraction pattern display often not more than 2-3 diffraction orders, and hence basic parameters like membrane thickness and equilibrium intermembrane distances are not readily available. In this report is shown, how the combination of a simple bilayer model with Fourier synthesis leads to a robust estimation of the bilayer thickness. In particular, it is demonstrated how with rather simple mathematical means two and three peak diffraction pattern can be exploited.