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Heterogeneous Rotational Diffusion Of A Fluorescent Probe In Lipid Monolayers, Christina M. Othon
Heterogeneous Rotational Diffusion Of A Fluorescent Probe In Lipid Monolayers, Christina M. Othon
Christina M Othon
The rotational correlation time of the lipid probe 1-palmitoyl-2-{6-[(7-nitro-2-1,3-benzoxadiazol-4-yl)amino]hexanoyl}-sn-glycero-3-phosphocholine (NBD-PC) is measured using fluorescence anisotropy for two lipid species. We measure the rotational diffusion in a monolayer of 1,2-Didecanoyl-sn-glycero-3-phosphocholine (DPPC) which displays a phase transition at room temperature from the liquid expanded to the liquid-condensed phase. The constant rotational diffusion of the probe throughout the phase transition reflects the measurement of dynamics in only the liquid-expanded phase. We contrast the dynamic changes during this phase coexistence to the continuous density increase observed in 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) at room temperature. We observe a non-exponential decay of the probe diffusion consistent with heterogeneity …
Crac Motif Peptide Of The Hiv-1 Gp41 Protein Thins Sopc Membranes And Interacts With Cholesterol., Alexander Greenwood, Jianjun Pan, Thalia Mills, John Nagle, Richard Epand, Stephanie Tristram-Nagle
Crac Motif Peptide Of The Hiv-1 Gp41 Protein Thins Sopc Membranes And Interacts With Cholesterol., Alexander Greenwood, Jianjun Pan, Thalia Mills, John Nagle, Richard Epand, Stephanie Tristram-Nagle
Prof. Stephanie Tristram-Nagle Ph.D.
This study uses low-angle (LAXS) and wide-angle (WAXS) X-ray synchrotron scattering, volume measurements and thin layer chromatography to determine the structure and interactions of SOPC, SOPC/cholesterol mixtures, SOPC/peptide and SOPC/cholesterol/peptide mixtures. N-acetyl-LWYIK-amide (LWYIK) represents the naturally-occurring CRAC motif segment in the pretransmembrane region of the gp41 protein of HIV-1, and N-acetyl-IWYIK-amide (IWYIK), an unnatural isomer, is used as a control. Both peptides thin the SOPC bilayer by approximately 3 A, and cause the area/unit cell (peptide+SOPC) to increase by approximately 9 A2 from the area/lipid of SOPC at 30 degrees C (67.0+/-0.9 A2). Model fitting suggests that LWYIK's average position …