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Azobenzene photoisomerization probes cell membrane viscosity
Arianna Magni1,2, Gaia Bondelli2, Giuseppe M Paternò1,2
1Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy. guglielmo.lanzani@iit.it.
Physical Chemistry Chemical Physics : PCCP
|April 4, 2022
Summary
Researchers developed a novel molecular viscometer using ZIAPIN2 to measure cell membrane viscosity. This probe accurately reflects how temperature affects membrane fluidity in Escherichia coli.
Area of Science:
- Biophysics
- Membrane Biology
- Molecular Probes
Background:
- Cell membrane viscosity is vital for molecular diffusion and disease pathogenesis.
- Quantitative nanoscale measurement of membrane viscosity is highly desirable.
- Understanding membrane rheology is crucial for cellular function.
Purpose of the Study:
- To investigate the photophysics of the amphiphilic azobenzene ZIAPIN2.
- To propose ZIAPIN2 as a novel probe for measuring cell membrane viscosity.
- To assess the viscosity of *Escherichia coli* membranes using ZIAPIN2.
Main Methods:
- Utilized ZIAPIN2's *trans-cis* photoisomerization for molecular viscometry.
- Employed time-resolved fluorescence spectroscopy.
- Measured fluorescence lifetimes of ZIAPIN2 in *E. coli* suspensions.
Main Results:
- Demonstrated ZIAPIN2's utility as a molecular viscometer.
- Observed a decrease in *E. coli* membrane viscosity with increasing temperature.
- Photophysical characterization supported membrane non-homogeneity and anisotropy.
Conclusions:
- ZIAPIN2 is a viable probe for quantitative nanoscale membrane viscosity measurements.
- The study provides insights into cell membrane rheology and temperature dependence.
- Findings contribute to understanding the complex dynamics of lipid bilayers.
