Sunday, April 5, 2020

cryo-electron microscopy: How the University of Minnesota ruled out Covid-19 as a lab engineered bioweapon




Wan, Y., Shang, J., Graham, R., Baric, R. S., & Li, F. (2020). Receptor recognition by novel coronavirus from Wuhan: An analysis based on decade-long structural studies of SARS. Journal of Virology. doi:10.1128/jvi.00127-20 
 "efforts to engineer a virus with the surface protein of the SHC014 coronavirus, found in horseshoe bats in China, and the backbone of one that causes human-like severe acute respiratory syndrome (SARS) in mice. The hybrid virus could infect human airway cells and caused disease in mice, according to the team’s results, which were published in Nature Medicine."  
https://www.the-scientist.com/news-opinion/lab-made-coronavirus-triggers-debate-34502

The lab coronavirus has a MOUSE "backbone" for the DNA. https://www.medicalnewstoday.com/articles/the-new-coronavirus-was-not-genetically-engineered-study-shows This article does not say MOUSE - but it should - why? I know because I read the actual science papers.

 




https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3372174/

The observation is that while SARS-CoV and closely related viruses from the civet can use ACE2 as a receptor, no bat coronavirus has been shown to use bat, human, or any other orthologs of ACE2 (, ). Further, sequence-based studies of the coronaviruses that have been found in bats suggest that their RBDs contain deletions spanning key residues required for mediating contact with ACE2 (, , , ). These observations necessitated alternate models of SARS-CoV emergence, and the currently favored model is one in which a bat coronavirus recombined with the coronavirus of a second, unknown species to create a novel hybrid virus that can use ACE2 ().

 Additionally, we show that RaTG13, a bat coronavirus closely related to SARS-CoV-2, also uses hACE2 as its receptor. The differences among SARS-CoV-2, SARS-CoV and RaTG13 in Structural basis of receptor recognition by SARS-CoV-2



pdf link by Fang Li 2016

OK so the Pangolin is from Guangdong if it was an intermediary species host....



On a visit to Shaoguan, Guangdong province, last year, the Guardian and staff from CBCGDF saw a caged facility previously used for attempted breeding of the notoriously hard-to-breed pangolin.
While there were no longer pangolin at the site, several locals near the facility confirmed the species had been raised there
https://www.theguardian.com/environment/2020/feb/25/coronavirus-closures-reveal-vast-scale-of-chinas-secretive-wildlife-farm-industry

They discovered that a bat coronavirus also binds to the ACE2 receptor, but poorly. A few mutations could have increased the ability of the bat virus to attach to the human receptor, allowing the hop to humans, according to the statement. The researchers also analyzed the structure of the spike proteins of pangolins, which could be an intermediate host between bats and humans, according to a previous Live Science report.
https://www.livescience.com/why-coronavirus-attaches-stronger-human-cells.html


















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