Crystal Structure of the Human Astrovirus Capsid Core
Engineering
BME 195 Senior Thesis Research Project
Human astroviruses are one of the leading causes of infectious diarrhea in young children, the elderly, and immunocompromised patients. Astroviruses are small, non-enveloped, and icosahedral RNA viruses with a capsid protein that forms the viral shell, containing the viral RNA genome. The atomic structure of the astrovirus viral capsid shell protein is not well known, but cryo-electron microscopy studies on astrovirus particles clarify that the capsid forms an icosahedral shell with globular dimeric spikes. In this project, my goal was to determine structural and functional properties of the human astrovirus capsid protein at the molecular level by investigating the capsid shell protein’s crystal structure. Because the astrovirus can survive the entirety of the gastrointestinal tract, the isolated capsid protein could be designed for therapeutic and targeted drug delivery within the digestive system. The astrovirus’ pathological effects would also be further understood by characterizing various structural components, providing opportunities for vaccine formulation against the virus. The capsid shell protein was expressed in a bacterial cell line, purified, and characterized to provide some insight into the human astrovirus’ icosahedral capsid shell stability and solubility. These results provided means for improved approaches in designing, expressing and purifying the human astrovirus capsid protein.
