‘Coronavirus uses dual receptors to infect host cells’
{ DR SANTOSH VERMA } ASST PROF, SGPGI SARS-CoV-2 is found to infect not only lungs, but other organs like gastrointestinal tract, kidney, brain, heart and immune cells.
A new breakthrough research published in the journal ‘Viruses’ by Dr Santosh Kumar Verma, assistant professor in the department of molecular medicine & biotechnology, Sanjay Gandhi Postgraduate Institute of Medical Sciences (SGPGIMS), has identified a new binding site in addition to receptor binding domain present in the spike-protein of coronavirus SARS-CoV-2.
Dr Santosh Kumar Verma led a national and international team of doctors for in this research.
Dr Verma said, “SARS-CoV-2 is found to infect not only lungs, but other organs like gastrointestinal tract, kidney, brain, heart and immune cells. To infect cells, SARS-CoV-2 uses its spike-protein receptor binding domain to latch with human angiotensin converting enzyme-2 (ACE2) receptor proteins present of the surface of host cells.”
Dr. Verma and the team of researchers from the US (University of Maryland), University of Delhi and Jawaharlal Nehru University, studied the virus and found that despite high sequence similarity and utilization of common host-cell receptor human ACE2 for virus infection, SARS-CoV-2 was more infectious than the closely related coronavirus SARS-Cov which led to relatively smaller outbreaks in 2003.
He said, “To understand this difference; using bio-informatics and molecular simulationbased approach, we found that in addition to receptor binding domain, an additional sialoside binding site is present in spikeprotein of SARS-CoV-2 but missing in SARS-CoV and is reminiscent of a related human infecting beta coronavirus MERS-CoV, which led to outbreak in Saudi Arabia and other West Asian countries in 2012. Apart from infecting humans,
MERS-CoV virus has also been reported to infect camels. This additional sialoside binding pocket helps coronavirus SARSCoV-2 to bind with sialic acid containing carbohydrates (a type of sugar) attached with different sialoglycoproteins present on the surface of different human organs which potentially support coronavirus SARS-CoV-2 to infect broad tissue types.”
Dr. Verma said that future study would help to better understand how this sialoside binding site in addition to receptor binding domain supported Covid-19 infection and transmission and this would possibly lead to identifying new potential therapeutics preventing such interaction.