GS Paper - 3 Biotechnology

An international team of researchers has analyzed genetic variation in ACE2, the receptor in humans for the Covid-19 causing SARS-CoV-2 virus from over 3 lakh individuals and identified key mutations that are predicted to make individuals more susceptible to the virus. The team was led by MedGenome, India/USA and SciGenom Research Foundation (SGRF), India. The team also reported ACE2 variants that can confer protection to individuals from the virus.

What

  1. Using recombinant DNA and protein expression technologies, they produced several human ACE2 variants and the viral Spike (S)-protein and tested them using biochemical assays to show that ACE2 variants have altered affinity for the S-protein.
  2. And, in a step further, they showed that the recombinant ACE2 with increased affinity for the S-protein blocked the virus from infecting the cell, in line with their predictions.
  3. Pointing out that understanding why some individuals are more severely affected than others is important for managing at-risk individuals, the team said developing effective drugs that can combat the virus will be important for managing the disease.

What is the ACE2 receptor?

  1. Angiotensin-Converting Enzyme 2 (ACE2) is a protein on the surface of many cell types.
  2. It is an enzyme that generates small proteins – by cutting up the larger protein angiotensinogen – that then go on to regulate functions in the cell.
  3. Using the spike-like protein on its surface, the SARS-CoV-2 virus binds to ACE2 – like a key being inserted into a lock – prior to entry and infection of cells.
  4. Hence, ACE2 acts as a cellular doorway – a receptor – for the virus that causes COVID-19.