Modulation of Membrane Fluidity to Control Interfacial Water Structure and Dynamics in Saturated and Unsaturated Phospholipid Vesicles

Abstract

The structure and dynamics of interfacial water in biological systems regulate the biochemical reactions. But, it is still enigmatic how the behavior of the interfacial water molecule is controlled. Here, we have investigated the effect of membrane fluidity on the structure and dynamics of interfacial water molecules in biologically relevant phopholipid vesicles. This study delineates that modulation of membrane fluidity through interlipid separation and unsaturation not only mitigate membrane rigidity but also disrupt the strong hydrogen bond (H-bond) network around the lipid bilayer interface. As a result, a disorder in H-bonding between water molecules arises several layers beyond the first hydration shell of the polar headgroup, which essentially modifies the interfacial water structure and dynamics. Furthermore, we have also provided evidence of increasing transportation through these modulated membranes, which enhance the membrane mediated isomerization reaction rate.

A Comparative Study on DMSO-Induced Modulation of the Structural and Dynamical Properties of Model Bilayer Membranes

“…In fact, our group and other groups previously have used C153 as a solvation and anisotropy probe in the phospholipid vesicle system and have concluded that C153 is located at the membrane or interface region rather than the water pool. 42,45,66,75 Coumarin dyes are very good markers of microenvironment polarity. Coumarin dyes have been extensively used to determine solvation dynamics due to its large Stokes shift, which is beneficial for comparison of two systems exhibiting small differences on the solvation dynamics time scale.…”

“…The femtosecond time-resolved upconversion data were collected in a commercially available fluorescence upconversion setup (Fluomax, IB Photonics) (Figure S1), in which a solid-state Ti-sapphire laser (Mai Tai HP, Spectra Physics) with a tunable range from 690 to 1040 nm was used as the laser source. , In our experiment, we used an 800 nm pulsed laser with a pulse width of 100 fs and a repetition rate of 80 MHz. In this setup, the fundamental 800 nm laser beam was focused onto a nonlinear β-barium borate (BBO) crystal to generate the frequency-doubled 400 nm visible lamp beam.…”

Real Space and Time Imaging of Collective Headgroup Dipole Motions in Zwitterionic Lipid Bilayers

“…Although almost all liquid crystalline lipid bilayers undergo large molecular displacements, their intermolecular interactions are lipid specific [4][5][6][7]. In biological membranes, lipids are in constant motion-due to thermal energy-and their movements impact their physical properties, such as bilayer viscosity, energy and heat transfer, lipid diffusion, and overall morphology [8][9][10][11][12]. Importantly, lipid bilayers are the underlying structures of biological membranes and define the cell's extracellular and intracellular environments [13,14], and enable a range of biological processes [15].…”

The effect of rhamnolipids on fungal membrane models as described by their interactions with phospholipids and sterols: An in silico study

“…By using phospholipid-based membrane mimetic models, it has been possible to show that RLs have the capability to influence membrane fluidity, a property highly dependent on phospholipid acyl chain length, saturation degree ( Hazel, 1995 ; Ernst, Ejsing, and Antonny, 2016 ; Sezgin et al, 2017 ; Fonseca et al, 2019 ; Mondal et al, 2020 ) and the concentration of sterols ( Hartmann, 1998 ; Piironen et al, 2000 ; Vance, 2000 ; Volkman, 2003 ). In particular, di-RLs are able to alter the lipid dynamics and lower the temperature of the gel-to-fluid phase transition ( Ortiz et al, 2006 ).…”