Coarse-grained model of tropoelastin self-assembly into nascent fibrils
A Tarakanova1,2, J Ozsvar3,4, A S Weiss3,4,5,6
1Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
Materials Today. Bio
|March 12, 2020
Summary
Tropoelastin monomers self-assemble into temperature-sensitive aggregates, forming fibrillar and globular structures. This directed assembly process, driven by hydrophobic interactions, is crucial for creating the elastic fibers essential for tissue integrity.
Area of Science:
- Biophysics
- Materials Science
- Biochemistry
Background:
- Elastin provides essential elasticity to tissues like lungs, blood vessels, and skin.
- Elastic fiber formation begins with tropoelastin monomer self-assembly into coacervate aggregates.
Purpose of the Study:
- To develop a coarse-grained model of tropoelastin assembly.
- To investigate the temperature sensitivity and structural characteristics of tropoelastin aggregates.
Main Methods:
- Developed an atomistically based coarse-grained model using a MARTINI framework.
- Incorporated an elastic network model to stabilize protein structures.
- Analyzed self-assembly dynamics and aggregate structures at different temperatures.
Main Results:
- Tropoelastin self-assembly forms dense aggregates up to ~70 nm, highly sensitive to temperature.
- Aggregates display a mix of fibrillar and globular substructures.
- Self-assembly is driven by hydrophobic domain interactions and water molecule reordering.
Conclusions:
- Coacervation drives directed assembly and domain orientation for downstream cross-linking.
- The model provides a framework for studying elastin and similar macromolecular assembly systems.
- Findings support the presence of heterogeneous cross-linking in elastic fibers.
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