The 2019 coronavirus (SARS-CoV-2) surface protein (Spike) S1 Receptor Binding Domain undergoes conformational change upon heparin binding

Courtney Mycroft-West; Dunhao Su; Stefano Elli; Scott Guimond; Gavin Miller; Jeremy Turnbull; Edwin Yates; Marco Guerrini; David Fernig; Marcelo Lima; Mark Skidmore

A P4SPR, multi-channel Surface Plasmon Resonance (SPR) instrument (Affinté Instruments; Montréal, Canada) was utilised with a gold sensor chip that was plasma cleaned prior to derivatization. A self-assembled monolayer of mPEG thiol and biotin mPEG was formed by incubating the chip in a 1 mM solution of these reagents at a 99:1 molar ratio in ethanol for 24 hrs 15 . The chip was rinsed with ethanol and placed into the instrument. PBS (1X) was used as the running buffer for the three sensing and a fourth background channel at 500 µl.min -1 , using an Ismatec pump. Twenty micrograms of streptavidin (Sigma, UK; 1mL in PBS) were injected over the four sensor channels. Subsequently, biotin-heparin (1 mL) was injected over the three sensing channels.