Rio de Janeiro, Jan 5 (efe-epa).- A group of Brazilian researchers has identified one of the factors that increases the possibility of infection by the British strain of the coronavirus, which is some 70 percent more infectious than other variants, the Foundation for Support of Research in Sao Paulo State (Fapesp).
The Brazilian researchers determined that the protein spike of the new strain, which is what forms the structure of the virus’s corona that gives the name to the coronavirus family, has greater molecular interactive strength with the ACE2 receptor, which is present on the surface of human cells and with which the SARS-CoV-2 virus connects to begin the process of infection.
“The increase in the strength of the molecular interaction of the new line is caused by a mutation already identified in amino acid 501 of the SARS-CoV-2 protein spike called N501Y, which gave the start to the new variant of the virus,” said Fapesp in a statement published on its Website.
The discovery was made by researchers at the University of Sao Paulo (USP) in a study financed by Fapesp and whose results were published on Tuesday on the bioRxiv international scientific web page in an article that has not yet been reviewed by other scientists.
The so-called British variant, dubbed B.1.1.7, has already been detected in some 20 countries – including two cases in Brazil – and is distinguished by a mutation that affects the way in which the virus affixes itself to human cells, something that makes it much more contagious than the earlier versions of the virus.
“We determined that the interaction between the protein spike of the new strain with the N501Y mutation is much greater than that presented by the first kind of the virus that was isolated in Wuhan (China),” said Geraldo Aleixo Passos, a USP researcher and one of the leaders of the study.
“There are other mutations in the genome of the new line that we’re not analyzing. We’re focusing on N501Y because it’s implicated in connection with the protein spike with ACE2,” he added.
To confirm their hypothesis, the research team performed tests with structures of the protein spike of the Wuhan coronavirus and with the new British strain, along with analysis using PyMOL public domain software.
“The results of the analyses showed that the mutation in the protein of the new variant establishes a greater interaction with the ACE2 receptor compared to the strain isolated in Wuhan,” Fapesp said.
“Adding the various weak connections between the mutant protein spike with the human ACE2 receptor resulted in stronger molecular interactions, which allow the virus to more easily penetrate the cells and trigger the replication system,” Passos said.
Despite having sparked alarm in the UK due to its high contagion rate, so far there is no evidence that the British strain results in more serious Covid-19 cases than the original strain, has a greater mortality rate or is resistant to the existing anti-Covid vaccines.
Brazil, one of the countries hardest hit by the pandemic, last week detected its first two cases of the British viral strain.
The South American giant has suffered the second-highest number of deaths from Covid-19 so far – about 200,000 – after the United States, and is in third place in terms of its caseload with almost 7.8 million confirmed cases, following the US and India.