Lateral Pressure Dependence of the Phospholipid Transmembrane Diffusion Rate in Planar-Supported Lipid Bilayers

Abstract

The dependence of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) flip-flop kinetics on the lateral membrane pressure in a phospholipid bilayer was investigated by sum-frequency vibrational spectroscopy. Planar-supported lipid bilayers were prepared on fused silica supports using the Langmuir-Blodgett/Langmuir-Schaeffer technique, which allows precise control over the lateral surface pressure and packing density of the membrane. The lipid bilayer deposition pressure was varied from 28 to 42 mN/m. The kinetics of lipid flip-flop in these membranes was measured by sum-frequency vibrational spectroscopy at 37 degrees C. An order-of-magnitude difference in the rate constant for lipid translocation (10.9 x 10(-4) s(-1) to 1.03 x 10(-4) s(-1)) was measured for membranes prepared at 28 mN/m and 42 mN/m, respectively. This change in rate results from only a 7.4% change in the packing density of the lipids in the bilayer. From the observed kinetics, the area of activation for native phospholipid flip-flop in a protein-free DPPC planar-supported lipid bilayer was determined to be 73 +/- 12 A(2)/molecule at 37 degrees C. Significance of the observed activation area and potential future applications of the technique to the study of phospholipid flip-flop are discussed.

Maltose neopentyl glycol-3 (MNG-3) analogues for membrane protein study

“…6 In addition, due to their cylindrical molecular geometry, the lipids self-assemble into a bilayer which provides a lateral pressure to the MPs. 7 However, these large membrane assemblies are not compatible with the current methods used in MP structure determination such as X–ray crystallography and nuclear magnetic resonance (NMR) spectroscopy. Therefore, an essential requirement for structural studies is that MPs are extracted from the membranes and maintained structurally and functionally intact in an aqueous solution.…”

Molecular Interactions between Amantadine and Model Cell Membranes

“…As flipflop proceeds with time, the net population difference in the two leaflets decreases, leading to the decrease in I CH 3 (or I CD 3 ). The lipid flip-flop kinetics can be analyzed by fitting the SFG timedependent signal using the following single exponential function: 42 (2) …”

In situ molecular level studies on membrane related peptides and proteins in real time using sum frequency generation vibrational spectroscopy

“…Over the last two decades, sum frequency generation (SFG) vibrational spectroscopy has been developed into a very powerful and highly versatile spectroscopic tool for surface and interfacial studies (Anglin, 2008; Bain et al, 1995; Baldelli et al, 2008; Belkin et al, 2005; Chen, 2007; Dreesen et al, 2004; Fourkas et al, 2007; Gautam et al, 2002; Gopalakrishnan et al, 2006; Gracias et al, 1999; Holman et al, 2004; Hopkins et al, 2005; Iwahashi et al, 2008; Kim et al, 2008; Koffas et al, 2004; Li et al, 2008; Ma et al, 2006; Moore et al, 2008; Opdahl et al, 2004; Richmond, 2002; Rupprechter et al, 2008; Shen et al, 2006; Shultz et al, 2002; Stiopkin et al, 2008; Voges et al, 2007; Yang et al,2002; Ye et al, 2008). SFG is a vibrational technique that is intrinsically surface-sensitive, requires small amounts of sample, and with which the experiments can be done in situ and in real-time (Allen et al, 2000; Bain, 1995; Belkin, et al, 2005; Buck et al, 2001; Chen, 2007; Chen and Chen, 2006; Chen and Clarke, 2005; Chen and Shen, 2002; Eisenthal, 1992; Gopalakrishnan et al, 2006; Gracias et al, 1999; Hopkins, et al, 2005; Koffas et al, 2004; Lambert et al, 2005; Miranda et al, 1999; Moore et al, 2008; Opdahl et al, 2004; Perry, et al, 2006; Richmond, 2001; Richmond, 2002; Shen, 1989; Shen et al, 2006; Shultz et al, 2000; Tadjeddine et al, 1996; Wang and Gan, 2005; Williams et al, 2002; Zhuang et al, 1996).…”