Molecular Dynamics Simulation of Protein Biosurfactants

Abstract

Surfaces and interfaces are ubiquitous in nature and are involved in many biological processes. Due to this, natural organisms have evolved a number of methods to control interfacial and surface properties. Many of these methods involve the use of specialised protein biosurfactants, which due to the competing demands of high surface activity, biocompatibility, and low solution aggregation may take structures that differ from the traditional head–tail structure of small molecule surfactants. As well as their biological functions, these proteins have also attracted interest for industrial applications, in areas including food technology, surface modification, and drug delivery. To understand the biological functions and technological applications of protein biosurfactants, it is necessary to have a molecular level description of their behaviour, in particular at surfaces and interfaces, for which molecular simulation is well suited to investigate. In this review, we will give an overview of simulation studies of a number of examples of protein biosurfactants (hydrophobins, surfactin, and ranaspumin). We will also outline some of the key challenges and future directions for molecular simulation in the investigation of protein biosurfactants and how this can help guide future developments.

Dynamic heterogeneity in complex interfaces of soft interface-dominated materials

“…This shows that even relatively simple stabilizers, can produce a wide range of heterogeneous surface phases. Similar simulations for large numbers of native globular protein molecules are not yet available because of computational limitations 32 . Recent simulations on interfaces stabilized by ellipsoidal colloidal particles, interacting through capillary interactions 33 , do however show similar types of heterogeneous structures, varying from randomly aggregated clusters at low surface coverage, to strand-like structures at high surface coverage.

Figure 4Structures formed by block copolymers at the liquid-vapor interface: ( a ) linear strands (effective dimension d e =1), ( b ) in-plane clusters (1≤ d e ≤2), ( c ) 3d clusters (2≤ d e ≤3), and ( d ) 3d films ( d e =3).

…”

Molecular Dynamics Simulations of Nanostructures Formed by Hydrophobins and Oil in Seawater

“…HPs have been considered in previous molecular simulation studies (e.g., see refs − and recent review papers and ). Most studies focused on systems involving a few HP molecules near fluid interfaces (air–water, oil–water, and lipid bilayers in contact with water) and their adsorption onto solid surfaces (self-assembled monolayers, silica) using all-atom (AA) and coarse-grained (CG) models.…”

Orientation and Conformation of Proteins at the Air–Water Interface Determined from Integrative Molecular Dynamics Simulations and Sum Frequency Generation Spectroscopy

“…For example, Kubiak and Mulheran suggested that ionic strength and structure of the surface could provide a molecular understanding for the discrepancies in experimental studies on the structure of lysozyme at charged silica interfaces . Similarly, simulations have been long used to understand the conformation of AWI-adsorbed proteins such as enzymes, antifreeze proteins, and hydrophobins, and a number of other globular proteins (i.e., β-lactoglobulin or β-casein). − However, there have been limited simulation studies that have looked at the assembly of lysozyme at the AWI. Recently, Cieplak et al presented a coarse-grained model for modeling proteins at the AWI by relating amino acid hydropathy to its preferred orientation at the interface .…”