Scientists identify synthetic mini-antibodies to fight Covid-19-health

In a groundbreaking study, scientists have identified synthetic mini-antibodies to fight Covid-19.

The ability of SARS-CoV-2 to infect cells depends on the interaction between the viral spike protein and the human cell surface protein ACE2. To allow the virus to attach to the cell surface, the spike protein binds to ACE2 using three finger-like projections called the receptor binding domain (RBD). Therefore, blocking RBD may prevent the virus from invading human cells. This can be done using antibodies.

Nanobodies, small antibodies found in camels and llamas, are promising tools against viruses due to their high stability and small size. Obtaining them from animals can be time consuming, but advances in technology have enabled the rapid selection of synthetic Nanobodies called sybodies. A technical platform for selecting sybodies from a large synthetic library was recently developed in the Markus Seeger laboratory at the University of Zurich and is now available for this study.

Looking for the best sybody for SARS-CoV-2

The Christian Low group at EMBL Hamburg searched existing libraries to find a body that could prevent SARS-CoV-2 from infecting human cells. First, they used the viral spike protein RBD as food and selected those sybodies that bind to them. They then tested sybodies selected according to their stability, effectiveness, and binding accuracy. Among the best binders, what is called sybody23 has proved to be particularly effective at blocking RBD.

To see exactly how sybody 23 interacts with the viral RBD, researchers in the Dmitri Svergun group at EMBL Hamburg analyzed the binding of sybody 23 to RBD by small-angle X-ray scattering. In addition, CSSB Martin Hallberg and Karolinska Institutet used cryo-EM to determine the structure of the complete SARS-CoV-2 spike bound to sybody 23. RBD switches between two positions. Ready to bind ACE2. In the “bottom” position, they are rolled up to hide from the human immune system. The molecular structure revealed that sybody 23 binds to RBD at both “top” and “bottom” positions, blocking the region where ACE2 normally binds. This ability to block RBD regardless of position may explain why sybody23 is so effective.

Finally, to test whether sybody 23 can neutralize the virus, Ben Murrell’s group at the Karolinska Institute used another virus called the Lentivirus to surface the SARS-CoV-2 spike protein. Modified to carry to. They observed that sybody23 succeeded in neutralizing the modified virus in vitro. Additional tests are needed to see if this sybody can stop SARS-CoV-2 infection in the human body.

Scientific cooperation during the blockade

“At this time, the spirit of collaboration was so great that everyone was willing to contribute,” said Christian Low, one of the chief scientists for the study. The researchers started the project shortly after receiving approval from EMBL leaders and reopened the lab during the blockade of Covid-19. They managed to select candidate sybodies and performed the analysis in just a few weeks.

“The methodology we used was already established for other research projects unrelated to SARS-CoV-2, so it was possible to obtain results very quickly. Development of these tools. It took quite a lot of time and resources, “says Low.

The results of this project have potential potential ways to treat Covid-19. In future studies, scientists will perform further analysis to see if sybody23 can be an effective treatment for Covid-19.

(This story is published from the news agency feed without changing the text.)

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