Developing an unfolding-incorporated coarse-grained polymer model for fibrinogen to study the mechanical behaviour

TL;DR

This paper introduces a novel coarse-grained polymer model that incorporates unfolding mechanisms of fibrinogen's D-domain, accurately capturing its complex elastic behavior and enabling large-scale fibrin network simulations.

Contribution

A new unfolding-incorporated coarse-grained model for fibrinogen that reproduces experimental mechanical properties and can be extended to other polymers with folded domains.

Findings

Model accurately matches experimental data

Captures unfolding of D-domains affecting elasticity

Potential to simulate large fibrin networks

Abstract

Fibrinogen is a protein found in blood that forms Fibrin polymer network to build a clot during wound healing process when there is a cut in the blood vessel. The fibrin fiber is highly stretchable and shows a complex mechanical properties. The fibrin monomer, Fibrinogen, has a very complex structure which is responsible for its unusual elastic behaviour. In this work, we focus on mechanism of unfolding of D-domain of Fibrinogen, and study its effect in the mechanical behaviour. We develop a coarse-grained (CG) bead-spring model for Fibrinogen which captures the unfolding of folded D-domains along with other necessary structural properties which affect the mechanical behaviour. The results from our unfolding-incorporated coarse-grained polymer (UCGP) model matches with the experimental results. This model has capacity to serve as the minimal unit to build a large-scale hierarchical structure of fibrin fiber and network to possibly unfold the mystery of fibrin's unusual elastic behaviour. This model can also be used for other polymers having folded domains or sacrificial bonds.