(294a) Experimental and Computational Comparison of the Surface Hydrophobicity of Viruses and Model Proteins

The physical characteristics of viruses needs to be understood in order to fully understand the interaction of viruses with host cells, as well as to create specific molecular recognition techniques to detect, purify, and remove viruses.  Viruses are generally believed to be positively charged at physiological pH, but there are few other defining characteristics.  Here, we have experimentally and computationally demonstrated that a nonenveloped virus is more hydrophobic than a subset of well-characterized proteins.  This adds an additional dimension to currently known virus characteristics.  In this study we determined the relative hydrophobicity of several proteins and compared them to a model nonenveloped virus.  The percentage of acetonitrile required to elute the proteins and virus from a C18 chromatography column was interpreted as the hydrophobic strength of each species. We obtained surface hydrophobicity data by coloring the surface of the protein and virus according to published hydrophobicity scales.  The amino acid sequence hydrophobicity was also determined. The results obtained indicate a strong correlation between surface hydrophobicity and the percent of acetonitrile needed to elute the proteins from a reverse phase column.  This demonstrates that hydrophobicity may be calculated, instead of experimentally determined.  We also determined that the nonenveloped virus we are modeling, porcine parvovirus (PPV) is highly hydrophobic.  Differences in hydrophobicity of proteins and viruses can be used to develop novel separation techniques to specifically adsorb viruses for detection, removal and purification, as well as interpret the interaction of viruses with cellular membranes.