A research team at Aarhus University in Denmark has developed a new molecule that attaches to the surface of SARS-CoV-2 virus particles. This attachment prevents the virus from entering human cells and spreading the infection.
An aptamer is a piece of DNA or RNA that folds into a 3D structure that can recognize a specific target molecule of interest. By attaching itself to the virus surface, the RNA aptamer prevents the Spike protein from serving as a key that allows the virus to enter a cell.
“We have started testing the new aptamer in rapid tests and we expect to be able to detect very low concentrations of the virus” says Professor Jørgen Kjems from Aarhus University who is the main author of the article which has just been published in the journal PNAS.
As per their paper which has been submitted for peer review: we report a 2′-fluoro protected RNA aptamer that binds with high affinity to the receptor binding domain (RBD) of SARS-CoV-2 spike protein, thereby preventing its interaction with the host receptor ACE2. A trimerized version of the RNA aptamer matching the three RBDs in each spike complex enhances binding affinity down to the low picomolar range. Binding mode and specificity for the aptamer–spike interaction is supported by biolayer interferometry, single-molecule fluorescence microscopy, and flow-induced dispersion analysis in vitro. Cell culture experiments using virus-like particles and live SARS-CoV-2 show that the aptamer and, to a larger extent, the trimeric aptamer can efficiently block viral infection at low concentration. Finally, the aptamer maintains its high binding affinity to spike from other circulating SARS-CoV-2 strains, suggesting that it could find widespread use for the detection and treatment of SARS-CoV-2 and emerging variants.