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Effects Of Ether Vs. Ester Linkage On Lipid Bilayer Structure And Water Permeability., S. Deren Guler, D. Dipon Ghosh, Jianjun Pan, John Mathai, Mark Zeidel, John Nagle, Stephanie Tristram-Nagle
Effects Of Ether Vs. Ester Linkage On Lipid Bilayer Structure And Water Permeability., S. Deren Guler, D. Dipon Ghosh, Jianjun Pan, John Mathai, Mark Zeidel, John Nagle, Stephanie Tristram-Nagle
Prof. Stephanie Tristram-Nagle Ph.D.
The structure and water permeability of bilayers composed of the ether-linked lipid, dihexadecylphosphatidylcholine (DHPC), were studied and compared with the ester-linked lipid, dipalmitoylphosphaditdylcholine (DPPC). Wide angle X-ray scattering on oriented bilayers in the fluid phase indicate that the area per lipid A is slightly larger for DHPC than for DPPC. Low angle X-ray scattering yields A=65.1A(2) for DHPC at 48 degrees C. LAXS data provide the bending modulus, K(C)=4.2x10(-13)erg, and the Hamaker parameter H=7.2x10(-14)erg for the van der Waals attractive interaction between neighboring bilayers. For the low temperature phases with ordered hydrocarbon chains, we confirm the transition from a tilted …
Structure And Water Permeability Of Fully Hydrated Diphytanoylpc., Stephanie Tristram-Nagle, Dong Joo Kim, Nadia Akhunzada, Norbert Kucerka, John Mathai, John Katsaras, Mark Zeidel, John Nagle
Structure And Water Permeability Of Fully Hydrated Diphytanoylpc., Stephanie Tristram-Nagle, Dong Joo Kim, Nadia Akhunzada, Norbert Kucerka, John Mathai, John Katsaras, Mark Zeidel, John Nagle
Prof. Stephanie Tristram-Nagle Ph.D.
Diphytanoylphosphatidylcholine (DPhyPC) is a branched chain lipid often used for model membrane studies, including peptide/lipid interactions, ion channels and lipid rafts. This work reports results of volume measurements, water permeability measurements P(f), X-ray scattering from oriented samples, and X-ray and neutron scattering from unilamellar vesicles at T=30 degrees C. We measured the volume/lipid V(L)=1426+/-1A(3). The area/lipid was found to be 80.5+/-1.5A(2) when both X-ray and neutron data were combined with the SDP model analysis (Kucerka, N., Nagle, J.F., Sachs, J.N., Feller, S.E., Pencer, J., Jackson, A., Katsaras, J., 2008. Lipid bilayer structure determined by the simultaneous analysis of neutron and …
Structure Of Fully Hydrated Fluid Phase Lipid Bilayers With Monounsaturated Chains., Norbert Kucerka, Stephanie Tristram-Nagle, John Nagle
Structure Of Fully Hydrated Fluid Phase Lipid Bilayers With Monounsaturated Chains., Norbert Kucerka, Stephanie Tristram-Nagle, John Nagle
Prof. Stephanie Tristram-Nagle Ph.D.
Quantitative structures are obtained at 30 degrees C for the fully hydrated fluid phases of palmitoyloleoylphosphatidylcholine (POPC), with a double bond on the sn-2 hydrocarbon chain, and for dierucoylphosphatidylcholine (di22:1PC), with a double bond on each hydrocarbon chain. The form factors F(qz) for both lipids are obtained using a combination of three methods. (1) Volumetric measurements provide F(0). (2) X-ray scattering from extruded unilamellar vesicles provides /F(qz)/ for low q(z). (3) Diffuse X-ray scattering from oriented stacks of bilayers provides /F(qz)/ for high q(z). Also, data using method (2) are added to our recent data for dioleoylphosphatidylcholine (DOPC) using methods …