Kit for detecting SARS.CoV.2 spike protein in biofluids

SARS.CoV.1-2.interacting.with.ACE2

Inspiration

The recent severe acute respiratory syndrome has spread so much rapidly and severely to induce World Health Organization to declare state of emergency over the new coronavirus SARS-CoV-2 pandemic. We recently analysed conformational changes occurring at SARS.CoV.2 spike protein trimer that favour interactions with human ACE2 triggering the fusion of virus protein envelope with human host cell plasma membranes.

*What we learned and how we built our models**

We might complete our analyses thanks to the recently cryo-em/crystallized solved structures of the whole SARS.CoV.2 spike protein in prefusion conformation and of the SARS.CoV.2 receptor binding domain (RBD) in complex with ACE2. Furthermore, thanks to the existence of crystallized/cryo-em solved structures about SARS.CoV.1 spike protein also in complex with ACE2 and/or neutralizing antibodies able to compete with ACE2 for the binding to SARS.CoV.1 spike RBD, we gained new insights about crucial ACE2 residues involved in direct interactions with SARS.CoV.1 and SARS.CoV.2 spike proteins.We shared results of our analyses on bioarxiv (https://www.biorxiv.org/content/10.1101/2020.04.17.046185v1) and the same results are under consideration on an important impacted international journal.

*Challenge*

We would like to express in vitro recombinant SARS.CoV.2 spike protein trimer, as well as SARS.CoV.2 spike protein RBD. We would also like to express the human wild type ACE2 and the engineered ones for verifying through binding assays if it is better to bind SARS.CoV.2 spike protein trimer, as well as SARS.CoV.2 spike protein RBD.

If our recombinant mutated ACE2 will be able to target efficiently SARS.CoV.2 spike RBD, we would like to create a prototype of a diagnosis kit able to detect spike protein in biological fluids.

Furthermore, according to our published results, our kit will represent the basis for building an analogous kit for detecting neutralizing antibodies present in human biological samples by using a mutated RBD, based on the acquired knowledge, able to target putative neutralizing antibodies even better than the SARS.CoV.2 spike wild type RBD.