HOUGHTON — A person doesn’t have to get sick to catch a virus. Researchers hope to catch viruses for detection and vaccinations by understanding their sticky outer layers.
The complex structures making the surface of a virus are small weaves of proteins that make a big impact on how a virus interacts with cells and its environment. A slight change in protein sequence makes this surface slightly water-repelling, or hydrophobic, causing it to stick to other hydrophobic surfaces.
A new paper, published recently in the scientific journal Colloids and Surfaces B: Biointerfaces (DOI: 10.1016/j.colsurfb.2017.02.011), details surface hydrophobicity in porcine parovirus (PPV).
Vaccines, Removal and Detection
Caryn Heldt, an associate professor of chemical engineering at Michigan Technological University, is the paper’s lead author. Currently, she is on sabbatical in St. Louis working with Pfizer to better understand how surface hydrophobicity could be used to improve vaccination production.
“Vaccine purification is all about surface interactions; if the components break apart, then they cannot be used as a therapeutic,” Heldt said adding that sensing and removing viruses also depend on surface interactions. “This may also help biologists understand a virus’ interactions with a cell.”
The main finding in this paper is that Heldt and her team compared experimental methods with computational methods to measure the surface chemistry.
Models and Experiments
Because virus hydrophobicity is relatively new and difficult to measure, Heldt’s team focused on using hydrophobicity models as a comparison. They compared the expected hydrophobicity measurements based on the main protein from the virus, called non-enveloped PPV, to well-studied model proteins that span a range of repelling or attracting water. Then they analyzed the samples using two kinds of chromatography — the analysis of chemical mixtures — along with fluorescent dyes that illuminate sticky, hydrophobic patches on the proteins.
The strong correlation between the computational and experimental results indicates that PPV — and likely other viruses — have a measurable hydrophobicity. Once the measurements are better understood, then Heldt and other researchers can better catch viruses. Doing so can improve detecting viruses, concentrating them and purifying vaccines.