Molecular Dynamics Simulations of Hydrophobins Encapsulating Organic Molecules: Can Hydrophobins be Used As Oil Dispersants?

Hydrophobins are a class of proteins produced by filamentous fungi in soil. Preliminary experiments suggest that these proteins can encapsulate oil in cylindrical ‘blobs’, or gases in cylindrical bubbles, which implies a striking surface activity. These properties, as well as the abundance and ease of biosynthetic manufacture of hydrophobins, suggest that they could be used as ‘natural’ oil spill dispersants. Here we report molecular dynamics (MD) simulations where we probed the stability of benzene blobs encapsulated by hydrophobins. Our simulations were performed using the Martini coarse-grained model, and probed system sizes that are comparable to oil blobs realized experimentally by the Russo group. Our results suggest that our model hydrophobins do encapsulate benzene forming structures that are not spherical but rather elongated, as indicated by simulation snapshots and measurements of the characteristic dimensions (moments of inertia) of the structures. The stability of the bubbles, as indicated by measurements of the root mean squared deviations (RMSDs) from the initial sizes, is assessed and discussed.