E. 30. Theory Comput. Q. Waheed, R. Tjörnhammar, and O. Edholm, Biophys. B, 17. H. Kenzaki, N. Koga, N. Hori, R. Kanada, W. Li, K.-i. S6a and S6c) within a reachable simulation timescale. Thus we analyzed the neutron data following the same procedure and applying the same model used for the POPC liquid phase . J. L. Klepeis, K. Lindorff-Larsen, R. O. Dror, and D. E. Shaw, Curr. After 30 min, the addition of TritonX-100 destroys all of the vesicles, allowing dithionite to react with all NBD molecules, and a final reading is made (AbsTX). The influence of the temperature on these dynamical processes is investigated. This is consistent with the fact that the transition from the liquid into the gel phase involves a drastic decrease in volume and area of the lipid molecules, which results in significant strengthening of the van der Waals attractive forces in the lipid bilayer. Using solid supported membranes, binding of cholera toxin to GMl containing POPC-membranes was quantified . (The model, kindly provided by Dr. S. C. Harvey of Georgia Tech, is of a discoidal HDL particle with ApoA-I[Δ1-33.] We further examined the spontaneous formation of a membrane bilayer, the temperature dependence of physical properties, the vesicle dynamics, and the POPC/DPPC two-component membrane dynamics of the CG lipid model, showing some promise. E, S. J. Marrink, A. H. De Vries, and A. E. Mark, J. Phys. For the two-site jump dynamics, EISF is given as follows : , where and are the probabilities of finding a bead in a trans or gauche conformation, respectively, with . Anyway, this model resulted to be unsuitable to describe the experimental EISF at and below the main transition temperature (data not shown). Recently, we have studied the liquid phase of hydrated DMPC and POPC bilayers  by means of quasi-elastic incoherent neutron scattering measurements and have identified three dominant dynamical processes on the ns-ps time scale, ascribed to three different motions of phospholipid molecules: (i) a fast uniaxial rotational diffusion, (ii) conformational, jump-like dynamics of the acyl chain along with threefold rotation of methyl groups, and (iii) overall diffusion dynamics confined within the first-neighbours cages. Google Scholar. When applied to organic or biological systems, which are hydrogen-rich, neutron scattering spectra are dominated by the high incoherent cross section of H and essentially provide information on single-particle dynamics. The bilayer is then moved into the liquid cell of the AFM and imaged in the same buffer. Again, increasing the temperature above Tm, the rates drop below the peak and follow the trend noted with the MPPC composition. Chem. Through the analysis of the temperature dependence of EISF, it was possible to infer that the gel to liquid phase transition entails (i) softening of the interchains interaction, (ii) an increase of the segmental motion occurring in the final part of the acyl chain, and (iii) a change of the diffusional dynamics from a very localized rattling-like motion to a confined diffusion. Andreas Janshoff, ... Claudia Steinem, in Membrane Science and Technology, 2003. Thus, in this condition, both the phase-separated state and the mixed gel phase can be stable. Use of the American Physical Society websites and journals implies that Okazaki, X.-Q. This option allows users to search by Publication, Volume and Page. The coexistence of two domains (4.2 6 0.4 nm and 3.3 6 0.3 nm) was observed during this temperature interval (Fig. Dithionite permeability through DPPC:DSPE-PEG(2000)(4%) membranes is represented in Fig. These data were fitted by means of a simple “bead model”: the phospholipid molecule was built up with several linked beads representing head groups, chain segments, head methyls, and tail methyls (see Figure 5). : Comput. 31. It is widely employed in the investigation of biological systems, including phospholipids bilayers [11, 27–29]. Koster, K.L., Sommervold, C.L. Figure 8 shows a compilation of the ion permeability rate constants (m2, in units of 1/min) for DPPC:DSPE-PEG(2000)(4%), POPC:DSPE-PEG(2000)(4%) and both lysolipid temperature-sensitive liposomes:DPPC:MPPC(10%):DSPE-PEG(2000)(4%) and DPPC:MSPC(10%):DSPE-PEG(2000)(4%) through the temperature range of 30–48°.