id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-327654-9g8zcxaa	Chi, Xiaojing	Humanized single domain antibodies neutralize SARS-CoV-2 by targeting the spike receptor binding domain	2020-09-10		.txt	text/plain	4993	302	51	Here, using SARS-CoV-2 spike receptor-binding domain (RBD) as a bait, we generate a panel of humanized single domain antibodies (sdAbs) from a synthetic library. Competitive ligand-binding experiments suggest that the sdAbs either completely block or significantly inhibit the association between SARS-CoV-2 RBD and viral entry receptor ACE2. To determine whether sdAbs targeted different antigenic regions on the SARS-CoV-2 RBD surface, we performed a competition-binding assay using a real-time biosensor (Fig. 3) . Fc fusion sdAbs in culture supernatants were affinity purified with HiTrap Protein A HP antibody purification columns ( Supplementary Fig. 2 ) and analyzed in both reducing and non-reducing conditions in Western blot using an anti-human IgG to detect Fc. As shown in Fig. 4c , the size of the constructed intact sdAb-Fc is around 80 KDa in the non-reducing condition, but a 40 KDa monomer was observed by prior treatment in reducing condition to break disulfide bonds.	./cache/cord-327654-9g8zcxaa.txt	./txt/cord-327654-9g8zcxaa.txt