As SARS-CoV-2 infiltrates the human body, its spike protein binds to cells, facilitating viral replication. A study by Tulane University, in collaboration with Florida International University, published in Protein Science, reveals a protein that may facilitate this binding process.
The research highlights perlecan LG3, a fragment of a proteoglycan commonly found in blood vessels and the brain, as capable of forming a stable bond with the COVID spike protein. This interaction potentially enhances the virus's ability to attach to cells, suggesting a role in COVID infections.
“The takeaway is this major extracellular matrix proteoglycan found in blood vessels throughout the body most likely plays a significant role in how the virus sticks to and infects cells,” explained Gregory Bix, co-corresponding author. “Perhaps this explains COVID’s impact on the vascular system and the brain, but LG3 seems to act as a sort of bridge for the virus.”
Using molecular modeling simulations, the study found that LG3 displayed a “high affinity stable interaction” with the COVID spike protein’s receptor-binding domain, the area that attaches to host cells. This attraction was confirmed using surface plasmon resonance instruments.
Further research is warranted to explore how mutations in different COVID strains may affect these binding interactions. Understanding the virus's cell entry mechanisms remains crucial for developing effective strategies against COVID-19 amidst its ongoing evolution.