IISc-CSIR Research to inactivate SARS-CoV-2

Researchers from Indian Institute of Science (IISc) recently conducted an experiment to inactivate the SARS-CoV-2 virus, in collaboration with the CSIR-Institute of Microbial Technology.

Key Facts

  • Researchers found the design of a new class of synthetic peptides. The peptides can block the entry of SARS-CoV-2 virus entry into cells, besides grouping the virus particles together. This way, the ability of virus to infect also reduces.
  • The need of this research got triggered due to rapid emergence of new strains of SARS-CoV-2 virus. It has decreased the protection offered by COVID-19 vaccines.

Protein-Protein interaction and new peptide

  • Protein-protein interaction is similar to that of a lock and a key. This interaction can be obstructed by synthetic peptide that similar to and competes with, stops the ‘key’ from binding to ‘lock’.
  • The new peptides can bind with and block the spoke protein present in the coronavirus.
  • This binding was characterised by cryo-electron microscopy (cryo-EM) and other such biophysical methods.
  • Designed peptides are hairpin-shaped and helical. Each of the peptides is capable to pair up with another peptide, forming a dimer.
  • Each dimeric ‘bundle’ provides two ‘faces’ for interacting with two target molecules. The two faces would bind with two different target proteins and lock all four in a complex. This way, it will block the targets.

S Protein Trimer

S protein is a trimer. It is a complex of three similar polypeptides. Every polypeptide comprises of a “Receptor Binding Domain (RBD)”, which sticks with the ACE2 receptor on surface of host cell. This interaction provides for viral entry into the cell. SIH-5 peptide was developed for blocking the RBD binding to human ACE2.

SIH-5 and s protein cross linking

When SIH-5 peptide come in contact with an S protein, one of its faces stick tightly with the three RBDs on S protein trimer, while the other face stick to the RBD from different S protein. This cross-linking helped SIH-5 in blocking both the S proteins at the same time.


The research on the peptide was supported as a part of “COVID-19 IRPHA call” of SERB Science and Engineering Research Board (SERB), which is a statutory body of the Department of Science and Technology (DST).



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