RBDwt and RBDmut kinetics by Bio-Layer Interferometry (BLI)
The analysis of binding kinetics of RBDWT and
RBDTRIP to ACE2-mFc was performed by Bio-Layer
Interferometry (BLI) using an Octet RED96e (Fortebio) instrument. High
precision Streptavidin (SAX, ForteBio, Fremont, CA, USA) biosensors were
saturated with 7.5 µg/ml biotinylated ACE2-mFc in BLI assay buffer (PBS,
0.1% BSA, 0.02% Tween 20) for 10 min. RBDWT and
RBDTRIP were prepared as twofold serial dilution
(typically 50, 25, 12.5, 6.25 and 3.125 nM) in BLI assay buffer plus
buffer blanks. Kinetic values were calculated by ForteBio data analysis
software using a 1:1 binding model.