A molecule to help virus in antibodies evasion

Context

A new study found that a natural molecule can block the binding of a subset of human antibodies to SARS-CoV-2.

About the key finding

• Instruments: The cryo-Em and X-ray crystallography is used to study.
• Key molecules: It is found that biliverdin and bilirubin can suppress the binding of antibodies to the coronavirusspike protein.
• The researchers discovered that biliverdin binds with the spike protein of SARS-COV-2.
• It gives it an unusual green colouration.
• The same natural molecule reduced antibody binding to the spike.
• Functioning: When SARS-CoV-2 infects a patient’s lungs it damages blood vessels and causes a rise in the number immune cells.
• This increases the levels of biliverdin and bilirubin in the surrounding tissues.
• The presence of these molecules gives virus more opportunity to hide from certain antibodies.
• The biliverdin attaches to the spike N-terminal domain and stabilises it. This causes the spike to not to open up and to expose parts of its structure.
• As a result some antibodies are not able to access their target sites and cannot bind to and neutralise the virus.
• Significance of study: The discovery could help in explaining that why some Covid-19patients can become severely ill despite having high levels of antibodies against the virus.