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Nonadditivity in interactions between three membrane-wrapped colloidal spheres.
Ali Azadbakht1, Billie Meadowcroft2, Juraj Májek3
1Soft Matter Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Leiden, the Netherlands.
Biophysical Journal
|December 30, 2023
Summary
Researchers experimentally confirmed nonadditive membrane interactions between three proteins. This finding, crucial for understanding collective protein behavior in cell functions, reveals preferred linear and triangular arrangements.
Area of Science:
- Biophysics
- Cell Biology
- Soft Matter Physics
Background:
- Cellular functions like signaling and endocytosis rely on coordinated membrane protein activity.
- Membrane deformations induced by proteins are key to their self-organization.
- Previous studies measured pairwise interactions, but nonadditive effects in larger groups were predicted but unconfirmed.
Purpose of the Study:
- To experimentally investigate and quantify nonadditive interactions between three membrane-deforming particles.
- To test predictions of nonadditivity in membrane-deformation-induced interactions.
- To identify favorable arrangements and understand the underlying mechanisms.
Main Methods:
- Utilized a colloidal model system with adhesive spheres and giant unilamellar vesicles.
- Measured interaction potentials and quantified arrangements of three membrane-deforming spheres.
- Employed Monte Carlo simulations to corroborate experimental findings.
Main Results:
- Provided the first experimental confirmation and quantification of nonadditive membrane-deformation-induced interactions.
- Identified two energetically favorable configurations: linear and triangular arrangements of the three spheres.
- Monte Carlo simulations supported the observed energy minima and linked them to reduced membrane deformation.
Conclusions:
- Membrane-deformation-induced interactions are nonadditive, impacting collective protein behavior.
- Specific arrangements (linear, triangular) are energetically favored due to reduced membrane deformation.
- The high symmetry observed suggests simple organizational rules for many membrane-deforming objects.
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