Figure 4.

Use of COSMO to enhance the binding of nanobodies against the RBD domain from the SARS‐CoV‐2 spike protein. a) Schematic illustration of caffeine‐inducible COSMO dimerization to form a noncovalently connected bivalent nanobody, thereby mimicking the role of Fc homodimerization module and enhancing its antigen recognition capability to engage the viral target. b,c) ELISA assessment of the reactivity of two COSMO‐tagged anti‐RBD nanobodies, b) H11‐D4 and c) VHH72, against SARS‐CoV‐2 RBD. Maltose binding protein (MBP) was used as a control. Datapoints represent the mean of three replicates and data were shown as mean ± s.e.m.