Presents the Friday Keck Center Teleconference*
The Hydrophobic Effect: What it is and what it is not
B. Montgomery Pettitt, Ph.D.,
University of Houston, Hugh Roy and Lille Cranz Cullen Distinguished Professor of Chemistry
4:00 pm Friday
Jan. 11th , 2008
(Refreshments at 3:45)
5.521 Levin Hall
Abstract: The hydrophobic effect between solutes in aqueous solutions plays a central role in our understanding of recognition and folding of proteins and self assembly of lipids. This effect has recently been restudied and new mechanisms proposed for its origins. Central to the debate is whether dewetting of the hydrophobic surfaces occurs prior to contact. The hydration behavior of two planar nanoscopic hydrophobic solutes in liquid water at normal temperature and pressure is investigated by calculating the potential of mean force at constant pressure as a function of the solute-solvent interaction potential using computer simulation. The importance of the effect of weak attractive interactions between the solute atoms and the solvent on the hydration behavior is demonstrated. Using two nanoscopic graphite-like plates as solutes, we show that just by tuning the attraction of the graphite plates with water one can observe either wetting or drying in the region between the two plates at several solvent diameters. We find the mechanism for attractive mean forces between the plates is very different depending on the nature of the solute-solvent interaction which has implications for the mechanism of the hydrophobic effect for biomolecules. ( http://www.chem.uh.edu/Faculty/Pettitt/ )
