Formation of Protein Networks between Mucins: Molecular Dynamics Study Based on the Interaction Energy of the System

Abstract

Molecular dynamics simulations have been performed for a model aqueous solution of mucin. As mucin is a central part of lubricin, a key component of synovial fluid, we investigate its ability to form cross-linked networks. Such network formation could be of major importance for the viscoelastic properties of the soft-matter system and crucial for understanding the lubrication mechanism in articular cartilage. Thus, the inter- and intra-molecular interaction energies between the residues of mucin are analyzed. The results indicate that the mucin concentration significantly impacts its cross-linking behavior. Between 160 g/L and 214 g/L, there seems to be a critical concentration above which crowding begins to alter intermolecular interactions and their energies. This transition is further supported by the mean squared displacement of the molecules. At a high concentration, the system starts to behave subdiffusively due to network development. We also calculate a sample mean squared displacement and p-variation tests to demonstrate how the statistical nature of the dynamics is likewise altered for different concentrations.

Interactions between Beta-2-Glycoprotein-1 and Phospholipid Bilayer—A Molecular Dynamic Study

“…The synovial fluid surrounding the bilayers contains a lot of different types of molecules that facilitate the lubrication. The most important components and their role in lubrication have been studied before [20,36,37,46]. β2-GP-1 is one of the proteins found in the synovial fluid, and in this paper, we focused on its influence on the behavior of the lipid bilayers present in the synovial fluid: DPPC and POPE.…”

“…From the time-dependent MSD, the linear viscoelastic complex shear moduli, G * , of a complex system can be obtained [45]. Each lipid molecule was approximated as a spherical object of radius R g , where R g is the mean radius of gyration computed overall for lipid molecules, as described in Reference [46]. The G * moduli can be obtained using the generalized Stokes-Einstein relation in the Fourier domain:…”