Self-organization and stability of magnetosome chains-A simulation study

Area of Science:

• Biophysics
• Cell Biology
• Materials Science

Background:

• Magnetotactic bacteria possess magnetosome chains, linear arrays of magnetic nanoparticles essential for cellular orientation in Earth's magnetic field.
• The precise mechanisms governing magnetosome chain assembly, stability, and rupture under external forces remain areas of active investigation.

Purpose of the Study:

• To computationally model and investigate the assembly dynamics and mechanical stability of magnetosome chains in magnetotactic bacteria.
• To elucidate the role of the cytoskeletal filament in magnetosome chain formation and resilience.

Main Methods:

• Development of a computational model simulating magnetosome attachment to a cytoskeletal filament and their magnetic interactions.
• Simulation of magnetosome chain response to external, rotating magnetic fields to probe mechanical stability.

Main Results:

• The cytoskeletal filament is critical for robust, linear assembly of magnetosomes, enabling cellular orientation and directed motility.
• Simulations identified threshold magnetic field strengths and orientations leading to chain rupture via two distinct events.
• A parallel magnetic field significantly accelerates magnetosome chain re-formation after rupture.

Conclusions:

• The filamentous backbone is essential for magnetosome chain integrity and function.
• Simulations provide single-cell level insights into magnetosome chain rupture dynamics, with implications for self-healing materials.
• The study highlights the complex self-assembly processes driven by competing alignment forces.