Severe acute respiratory Coronavirus Spike trimer (S1+S2), with 682-685>A, K986P, V987P, and D614G mutations, Genbank Accession No. MN908947, a.a. 1-1213, with a C-terminal His-tag, expressed in a HEK293 expression system. MW=137 kDa. This protein runs at a higher M.W. by SDS-PAGE due to glycosylation.