Structural Studies on Respiratory Syncytial Virus Fusion Glycoprotein
Engineering
Senior Thesis Research in DuBois Lab (BME 195)
Respiratory syncytial virus (RSV) infects almost all children by 3 years of age and often leads
to infant hospitalization and childhood wheezing. Currently, the only intervention available for
RSV is the monoclonal antibody palivizumab. There is an urgent need to find other methods for
treating or preventing RSV infection. RSV contains an envelope glycoprotein known as the F
protein. It is a trimeric protein that can form two conformations, pre and post-fusion
conformations. When the RSV virion attaches to a host cell, the F protein rearranges structurally
from the pre-fusion form to the post-fusion form, resulting in fusion of the human and virus cell
membranes and delivery of the virus nucleocapsid inside the human cell. Studies have shown that
RSV neutralizing antibodies elicited after infection primarily recognize the pre-fusion
conformation of the RSV F protein. Hence, the pre-fusion F protein of RSV may be the best target
for vaccine development. However, the metastable nature of the pre-fusion conformation makes
this challenging because it spontaneously transitions to the post-fusion form when expressed
recombinantly. To understand the role and molecular mechanisms of the RSV F protein in host
cell binding, my goals were to: engineer stable RSV F in the pre-fusion conformation, and
crystallize the RSV F pre-fusion protein then soak these crystals with a mimetic of heparan sulfate,
which has been shown to be an important binding partner for other paramyxoviruses.
Understanding the interactions of heparan sulfate with RSV F will provide new insights into the
mechanism of RSV fusion after host cell binding. I have expressed and purified RSV F and since
this project is still ongoing, the structural work is yet to be completed.
