Current Affairs

A molecule to help virus in antibodies evasion

  • Posted By
    10Pointer
  • Categories
    Science & Technology
  • Published
    24th Apr, 2021

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.

Bilirubin

  • Bilirubin is a yellowish substance in blood.
  • It forms after red blood cells break down.
  • It then travels through the liver, gallbladder, and digestive tract before being excreted.
  • Bilirubin level is found in between 0.3 and 1.2 milligrams per deciliter (mg/dL).

Biliverdin

  • Biliverdin is a green tetrapyrrolic bile pigment.
  • It is a product of heme catabolism.
  • It is the pigment responsible for a greenish color which is sometimes seen in bruises.
  • Biliverdin has been found in excess in the blood of humans suffering from hepatic diseases.