Fig. 1: SARS-CoV2 RBD in vitro selection.
From: SARS-CoV-2 variant prediction and antiviral drug design are enabled by RBD in vitro evolution
Six consecutive libraries were created by error-prone PCR (inserting 1–5 mutations per gene) to increase RBD domain stability and binding to the ACE2 receptor. Libraries S1 and S2 were selected for higher expression at 30 °C and 37 °C, respectively. A single clone, I358F, was identified (Extended Data Fig. 1). Based on this stabilized RBD, we created libraries B3–B5, randomizing residues 431–528. From each selected library, the pool of enriched clones was used as a template for the subsequent library. The last library B6(FA) was created by pre-equilibrium selection of randomly mutated residues 336–528. Multiple clones from each library were sequenced and monitored for affinity and stability (Tables 1 and 2).
