Fig 1.
A Two-dimensional X-ray intensity maps measured at 88% RH for a fresh RBCcm sample and RBC collected from RC that was stored for 2 and 5 weeks respectively. Up to 6 orders of lamellar peaks were observed. B Specular reflectivity as determined from the integrated intensity marked as white rectangle. C X-ray intensity determined along the meridional angle Φ as indicated by the white line in A. The degree of orientation was determined by fitting Hermans orientation function. D Relative electron density profile determined from a 1-dimensional Fourier analysis. Maxima around |z| = 20 Å indicate the location of the electron-rich head-groups of the membranes while the electron density is reduced in the bilayer center.
Table 1.
Structural parameters and membrane bending modulus κ determined from XRD and XDS experiments.
Fig 2.
A—C Background corrected in-plane X-ray intensity profiles. Three peaks resulting from liquid ordered lo and liquid disordered ld lipid domains, as well as α-helical protein structures were observed and fits are shown in blue, green and red respectively. The domain sizes were determined as described in Materials & methods and are expressed as the edge length of the domain. They are plotted in D and E.
Fig 3.
A Two-dimensional X-ray intensity maps measured at 99.9% RH. A diffuse cloud of X-ray signal was observed as the result of out-of-plane fluctuations. Line-cuts at qz = 2.5 ⋅ q1 are depicted in B. The bending modulus κ and membrane interaction modulus B were determined by fitting S(q) to the data, and are visualized as bar graph in C and D.
Fig 4.
A 3-dimensional render of a simulated RBCcm patch after 2 μs. Lipid molecules are displayed as rods symbolizing molecular bonds. Cholesterol is depicted as red spheres. Each lipid species (Phosphatidylcholine, PC; Ceramide, CER; Monoglucosyl lipids, MG; Diacylglycerol lipids, DG; Fatty acids, FA; Sphingomyelin, SM; Phosphatidylethanolamine, PE; Phosphatidylserine, PS; Phosphatidylglycerol, PG; Phosphatidic acid, PA; Phosphatidylinositol, PI) are represented by different colors indicated in the legend. B Cholesterol density maps averaged over the last 800 ns of the simulation. Red indicates cholesterol rich areas while blue represents cholesterol depletion. C Mass density profiles averaged over the last 800 ns of the simulation for the entire membrane patch (System) and the cholesterol head groups. D Fluctuation spectrum of the 42 day old membrane patch. The bending modulus κ was determined by fitting Helfrich–Canham (HC) theory.
Table 2.
Structural parameters and bending modulus κ determined from MD simulations.