According to a new virological research paper published in Nature-structure and Molecular Biology, a professional academic journal of Springer Nature, through a comparative study on the structure of the novel coronavirus (SARS-CoV-2) and its relative bat virus RaTG13’s spike glycoprotein, which allows the virus to bind to the cell and enter the cell, it provides information for further understanding the evolution of novel coronavirus’s spike process. This may be of reference significance for vaccine design.
According to the paper, researchers believe that bat coronavirus may be the evolutionary precursor of novel coronavirus, and previous studies have found that the genetic relationship between bat virus RaTG13 and novel coronavirus is the closest known relationship. However, it is not clear how novel coronavirus evolved to infect humans, or whether it was transmitted through an intermediate host or directly to humans.
By comparing the spike glycoproteins of novel coronavirus and RaTG13, the correspondence authors Antoni Wrobel and Donald Benton, virologist of Francis Crick Institute in London, England, found that although they were similar in structure, the form of novel coronavirus spike glycoprotein was more stable, and its affinity to human receptor protein ACE2 was about 1000 times higher.
They also found that the Flynn protease cleavage site on novel coronavirus’s spinous process may be beneficial to the virus because it may promote the binding of the virus to the receptor on the cell. Based on these observations, the authors believe that bat viruses similar to RaTG13 are unlikely to infect human cells, which also supports the theory that novel coronavirus evolved from the recombination of different coronavirus genomes.
The authors point out that the novel coronavirus prickle glycoprotein they studied is of high resolution, almost complete, and has a more outer loop, than previously reported, which may be of great significance for vaccine research and design.