Stabilization of full-length S-protein of SARS-Cov-2 coronavirus in SMA polymer for electron microscopy study
In: Vestnik Moskovskogo universiteta. Seria 16. Biologia, Band 78, Heft №3s, 2023, S. 27-32
A detergent-free protocol for purification of the coronavirus prefusion S-protein using styrene-
maleic acid copolymer (SMA) was developed. Expression of the S-protein was carried out in
HEK293T cells. Two solubilization methods were used to purify and prepare the S-protein for
microscopy: in NP-40 detergent and as part of SMA. The resulting preparations were examined
in an electron microscope, and the particles of purified S-proteins were classified. Analysis of
two-dimensional projections of the particles showed that the use of lipodiscs for solubilization
leads to lower mobility of the purified protein on the substrate, compared to the protein in the
detergent, which may further contribute to obtaining higher resolutions when studying the
structure of membrane proteins.