Researchers at Linköping University in Sweden have found that the human immune system can affect the spike protein on the surface of the new coronavirus, resulting in a misfolded spike protein called amyloid. There may be a link between harmful amyloid production and COVID-19 symptoms, or cause blood clotting disorders. The findings were published today in the Journal of the American Chemical Society.
In people with severe and prolonged COVID-19, organs other than the lungs can be severely affected. Symptoms and damage, such as blood clotting disorders, may persist in areas such as the heart, kidneys, eyes, nose, and brain. After studying diseases such as Alzheimer’s disease caused by protein misfolding, the researchers noted that COVID-19-related symptoms share many similarities with diseases caused by protein misfolding.
Proteins fold in specific ways, resulting in specific three-dimensional structures that affect protein function. In addition to this shape, proteins can take on another form. More than 30 different proteins are known to have this disease-related alternative shape, known as amyloid.
Through computer simulations, the researchers found that the spike protein of the new coronavirus contains seven different sequences that may produce amyloid. In experimental tests, three of the seven sequences met the researchers’ criteria to be counted as amyloid-producing sequences. In addition, they produced fibers that looked like long threads when examined under an electron microscope.
But do these fibers form spontaneously? Many diseases, such as Alzheimer’s, occur before the body’s process of slicing large proteins into smaller pieces, which in turn produces harmful amyloid. New research shows that an enzyme from neutrophils, a type of white blood cell from the immune system, cuts the coronavirus’ spike protein. This enzyme is released in large quantities from the early stages of neutrophil infection. When the spike protein is cleaved, it produces precise protein fragments that, according to the analysis, are most likely to produce amyloid. When the researchers mixed pure spike protein with neutrophil elastase, the unusual fibers were created.
Post time: May-27-2022