Knowledge of the sites at which the virus binds to its host cell and understanding its binding behaviour are of fundamental importance for designing active ingredients that can stop the binding process and also for the development of diagnostic tests based on such binding. Since SARS-CoV-2 has many spike proteins on its surface, bindings can appear at several binding peptides if the density of the DNA lever is suitably adjusted. Compared with the affinity of the first binding, every further binding leads to a significant increase in affinity. This has already been proven in influenza viruses by the Bioanalytics and Bio-processes department of Fraunhofer Institute for Cell Therapy and Immunology (IZI-BB).
Accordingly, multivalent binding partners provide a promising option for the inhibition of viruses on the host cell. The binding kinetics of these multi-valent bonds can be established with the help of the SwitchSense technology. Virus-like particles or surface-modified particles with bound spike proteins are to be used for these measurements. Moreover, the size of the viruses can also be determined using the SwitchSense technology, which provides a further measurement parameter for characterising a virus sample in terms of its homogeneity and a further characteristic for differentiating various viruses.
In the CoronaSense project, a nano-structure with a nucleic acid scaffold and virus-binding peptide moieties (patent: WO2018215660A1) is to be exploited by the Fraunhofer IZI DNA Nano-Systems Working Group.