Open AccessPurification and characterization of the receptor‐binding domain of SARS‐CoV‐2 spike protein from Escherichia coli
Author(s) -
He Yunxia,
Qi Jinming,
Xiao Lucheng,
Shen Lijuan,
Yu Weili,
Hu Tao
Publication year - 2021
Publication title -
engineering in life sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.547
H-Index - 57
eISSN - 1618-2863
pISSN - 1618-0240
DOI - 10.1002/elsc.202000106
Subject(s) - glycosylation , epitope , escherichia coli , hek 293 cells , virus , biology , virology , dissociation constant , antibody , viral entry , receptor , chemistry , microbiology and biotechnology , viral replication , biochemistry , gene , genetics
Abstract SARS‐CoV‐2 is responsible for a disruptive worldwide viral pandemic, and renders a severe respiratory disease known as COVID‐19. Spike protein of SARS‐CoV‐2 mediates viral entry into host cells by binding ACE2 through the receptor‐binding domain (RBD). RBD is an important target for development of virus inhibitors, neutralizing antibodies, and vaccines. RBD expressed in mammalian cells suffers from low expression yield and high cost. E. coli is a popular host for protein expression, which has the advantage of easy scalability with low cost. However, RBD expressed by E. coli (RBD‐1) lacks the glycosylation, and its antigenic epitopes may not be sufficiently exposed. In the present study, RBD‐1 was expressed by E. coli and purified by a Ni Sepharose Fast Flow column. RBD‐1 was structurally characterized and compared with RBD expressed by the HEK293 cells (RBD‐2). The secondary structure and tertiary structure of RBD‐1 were largely maintained without glycosylation. In particular, the major β‐sheet content of RBD‐1 was almost unaltered. RBD‐1 could strongly bind ACE2 with a dissociation constant (K D ) of 2.98 × 10 –8 M. Thus, RBD‐1 was expected to apply in the vaccine development, screening drugs and virus test kit.