MODULAR NANOTRANSPORTERS CAPABLE OF BINDING WITH SARS-COV-2 VIRUS NUCLEOCAPSID PROTEIN INTO TARGET CELLS

Abstract

Based on the literature data, an antibody-like molecule, a monobody, was selected that is capable of interacting with the nucleocapsid protein (N-protein) of the SARS-CoV-2 virus with high affinity (dissociation constant 6.7 nM). We have previously developed modular nanotransporters (MNTs) to deliver various molecules to a selected compartment of target cells. In this work, a monobody to the N-protein of the SARS-CoV-2 virus was included in the MNT using genetic engineering methods. In this MNT, a site for the cleavage of the monobody from the MNT in endosomes was also introduced. It was shown by thermophoresis that the cleavage of this monobody from MNT by the endosomal protease cathepsin B leads to a 12-fold increase in the affinity of the monobody for the N-protein. Cellular thermal shift assay showed the ability of the obtained MNT to interact with the N-protein in A431 cells transfected with the SARS-CoV-2 N-protein fused to the mRuby3 fluorescent protein.