Doctor of Philosophy (PhD)
This dissertation contains fundamental, classical molecular simulation studies of the properties of hydrophobins (a unique family of surface-active proteins produced by filamentous fungi in soil) near interfaces involving gas, oil, water, organic solvents and polymers. These studies are relevant to possibly using hydrophobins as natural oil dispersants and in processing of polymers. Preliminary studies by the Russo group suggest that these small surface-active proteins can encapsulate oil, gases and polymers in cylindrical structures. We have performed classic molecular dynamics (MD) simulation and potential of mean force (PMF) calculations of a class I hydrophobin EAS using both all-atom and coarse-grained representations. The interfacial properties of these hydrophobins at gas/water and oil/water interfaces were probed, and our simulation results qualitatively agree with experimental observations. According to the PMF calculation results, EAS molecule was likely to stay at the hydrophobic/hydrophilic interface, and the adsorption behavior of EAS at the interface was strong and irreversible. We performed MD simulations using Martini coarse-grained (CG) models to gain insight into the stability of nm-sized ‘blobs’ formed by the assembly of hydrophobin around oil. Finally, we developed a Martini model for Poly(ã-stearyl á,L-glutamate), PSLG, and used it to perform MD simulations of PSLG molecules near a hydrophobin-coated hydrophilic-hydrophobic interface. These simulations suggest that initial alignment of the PSLG chains, PSLG concentration and solvent type may affect the final alignment of the PSLG chains.
Document Availability at the Time of Submission
Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.
Chen, Yuwu, "Molecular Simulation Studies of Hydrophobins near Gas, Oil and Water Interfaces" (2016). LSU Doctoral Dissertations. 4260.
Benton, Michael G