Hank Ashbaugh

There are many open questions regarding the hydration of solvent-exposed, non-polar tracts and pockets in proteins. Although water is predicted to de-wet purely repulsive surfaces and evacuate crevices, the extent of de-wetting is unclear when ubiquitous van der Waals interactions are in play. The structural simplicity of synthetic supramolecular hosts imbues them with considerable potential to address this issue. To this end, here we detail a combination of densimetry and molecular dynamics simulations of three cavitands, coupled with calorimetric studies of their complexes with short-chain carboxylates. Our results reveal the range of wettability possible within the ostensibly identical cavitand pockets — which differ only in the presence/position of the methyl groups that encircle the portal to their non-polar pockets. The results demonstrate the ability of macrocycles to template water cavitation within their binding sites and show how the orientation of methyl groups can trigger the drying of non-polar pockets in liquid water, suggesting new avenues to control guest complexation.

Hank Ashbaugh was born in Chicago, IL and grew up in Charlotte, NC. He graduated from North Carolina State University with a BS in Chemical Engineering in 1992. He subsequently attended graduate school in Chemical Engineering at the University of Delaware. After defending his PhD in 1998, Hank conducted post-doctoral research at Lund University in Sweden, Princeton University, and Los Alamos National Laboratory. Hank joined Tulane University’s Department of Chemical and Biomolecular Engineering in 2004 as an Assistant Professor, rising through the ranks to Professor in 2016. Today, Hank serves as the Department Chair of Chemical and Bimolecular Engineering. His research interests include the multiscale simulation and theory of self-assembly and hierarchical organization in complex fluids including surfactant solutions, polymer melts and solutions, and biopolymer gels and networks to advance self-assembly as a labile tool for building tailored nanostructured materials.

• Time: 11:00 AM
• Location: 206 Furnas Hall