Imaging non-classical mechanical responses of lipid membranes using molecular rotors

DOI: 10.1039/D0SC05874B

Authors: Miguel Paez-Perez (Imperial College London) , Ismael López-Duarte (Imperial College London; Universidad Autónoma de Madrid) , Aurimas Vyšniauskas (Imperial College London; Center of Physical Sciences and Technology) , Nicholas J. Brooks (Imperial College London) , Marina K. Kuimova (Imperial College London)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemical Science , VOL 40

State: Published (Approved)
Published: December 2020

Abstract: Lipid packing in cellular membranes has a direct effect on membrane tension and microviscosity, and plays a central role in cellular adaptation, homeostasis and disease. According to conventional mechanical descriptions, viscosity and tension are directly interconnected, with increased tension leading to decreased membrane microviscosity. However, the intricate molecular interactions that combine to build the structure and function of a cell membrane suggest a more complex relationship between these parameters. In this work, a viscosity-sensitive fluorophore (‘molecular rotor’) is used to map changes in microviscosity in model membranes under conditions of osmotic stress. Our results suggest that the relationship between membrane tension and microviscosity is strongly influenced by the bilayer's lipid composition. In particular, we show that the effects of increasing tension are minimised for membranes that exhibit liquid disordered (Ld) – liquid ordered (Lo) phase coexistence; while, surprisingly, membranes in pure gel and Lo phases exhibit a negative compressibility behaviour, i.e. they soften upon compression.

Subject Areas: Biology and Bio-materials, Chemistry


Instruments: I22-Small angle scattering & Diffraction

Added On: 03/02/2021 13:25

Documents:
d0sc05874b.pdf

Discipline Tags:

Biochemistry Chemistry Life Sciences & Biotech

Technical Tags:

Scattering Small Angle X-ray Scattering (SAXS) Wide Angle X-ray Scattering (WAXS)