Multilayer membrane

Figure 10.4 (A) The DNA interaxial distance dDNA and the interlayer distance d in the L°a phase (Figure 10.2) plotted as a function of Lipid/DNA (UD) (wt/wt) ratio at the isoelectric point of the0 complex DOTAP/DNA=2.2. dDNA is seen to expand from 24.5 A to 57.1 A. The solid line through the data is the prediction of a packing calculation where the DNA chains form a space rilling one-dimensional lattice. (B) Schematic drawing of DNA-membrane multilayers showing the increase in distance between DNA chains as the membrane charge density is decreased (i.e., as DOpc increases) at the isoelectric point (Adapted from Raedler et al., 1997 Kohover etal., 1999).

Fig. 17. The ratios of the integrated intensities of the laimnelar reflections R(h/h ) = ([S(h)/S(h )], — [S(h)/S(h )]2)/[S(h)/S(h )l2 for a reconstituted cytochrome oxidase membrane multilayer. The subscript 1 denotes the incident X-ray energy and the index 2 corresponds to an energy far from the absorption edge, h = 4, h = 2, 3, 5 and 6 at incident X-ray energies near the iron K-absorption edge ( ). The f dispersion is most significant with h = 2 and h = 6. There is no dispersion at wavelenghts near the Co K-absorption edge (O)- After Stamatoff et al.

Studies with orientated membrane multilayers have suggested that the Fe-Fe axis of the FeS centre lies in the membrane plane [206,236]. Based on pH-dependent inhibition by a ubiquinone analogue, Harmon and Struble [237] placed the FeS centre on the C side of the membrane. However, their results would also be consistent with a location inside the membrane domain, provided that there is protonic communication with the aqueous C phase. The observed interactions between Q and the FeS cluster (above) suggest, together with the location of ubiquinone in the hydrophobic domain of the membrane (see below), that the FeS centre is buried within this domain. 

Schwartz, S., Cain, J. E., Dratz, E. A., Blasie, J. K. An Analysis of Lamellar X-Ray Diffraction from Disordered Membrane Multilayers with Application to Data from Retinal Rod outer Segments. Biophys. J. IS, 1201—1233 (1975)... 

Flelfrioh W 1977 Sterio interaotion of fluid membranes in multilayer systems Z. Naturf. a 33 305... 

In PEMFCs, the membrane electrode assembly (MEA, Eig. 15.2a) is a multilayer sandwich composed of catalytic layers (CLs) where electrochemical reactions take place, gas-diffusion media providing access of gases to the CLs, and a proton exchange membrane (PEM) such as Nafion . The CL is a multiphase multicomponent medium comprising ... 

Compression of the PS II membrane monolayer shows that the monolayer collapses at a relatively low surface pressure, at around 20mN/m. This can be attributed to the formation of a multilayered structure [8] and some of PS II membrane fragments diffuse into the subphase. This observation further indicates that PS II membranes can only marginally stay at the air-water interface and one must be very careful in choosing the experimental parameters. 

The A F-A isotherm of PS II core complex is rather different from that of PS II membrane (Fig. 4). The surface potential of a monolayer of PS II core complex increases slightly as the molecular area is compressed from 600 to about 150nm, while surface pressure changes from 5 to 35mN/m. Further compression results in a sharper increase in surface potential. The surface potential starts to decrease only after the surface area is compressed to about 80 nm or surface pressure becomes larger than 40mN/m. This is consistent with the previous discussion that PS II core complexes form a more ordered monolayer structure at relatively high surface potential and will not form multilayered... 

Nakamura, M., Kiyohara, S., Saito, K. Sugita, K., and Sugo, T., High resolution of DL-tryptophan at high flow rates using a bovine serum albumin-multilayered porous hollow-fiber membrane, Anal. Chem., 71, 1323, 1999. 

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