SARS-CoV-2 Spike Trimer Protein, His Tag (XFG) (MALS verified)

SARS-CoV-2 Spike Trimer Protein, His Tag (XFG) (SPN-S5229) is expressed from human 293 cells (HEK293) . It contains AA Val 16 - Pro 1213 (Accession # QHD43416.1 (T19I, R21T, T22N, A27S, S31P, S50L, V127F, G142D, F157S, R158G, K182R, R190S, L212I, V213G, L216F, H245N, A264D, I332V, G339H, R346T, K356T, S371F, S373P, S375F, T376A, R403K, D405N, R408S, K417N, N440K, K444R, V445R, G446S, N450D, L452W, L455S, F456L, N460K, S477N, T478K, N481K, E484K, F486P, N487D, Q493E, Q498R, N501Y, Y505H, E554K, A570V, T572I, D614G, P621S, H655Y, N679K, S680P, P681R, N764K, D796Y, S939F, Q954F, N969K, D1084G, P1143L) ) . The recombinant protein is expressed from human 293 cells (HEK293) with T4 fibritin trimerization motif and a polyhistidine tag at the C-terminus. Proline substitutions (F817P, A892P, A899P, A942P, K986P, V987P) are introduced to stabilize the trimeric prefusion state of SARS-CoV-2 S protein.

Product Specifications

Background

SARS‑CoV‑2 XFG, also known as the “Stratus” variant, is a recombinant Omicron lineage derived from LF.7 and LP.8.1.2, first detected in January 2025 in Southeast Asia2. It carries key spike mutations such as T22N, S31P, K182R, R190S, R346T, K444R, V445R, F456L, N487D, Q493E, and T572I, some linked to enhanced immune evasion. By mid‑2025, XFG spread to over 38 countries, becoming dominant in parts of India and the United States1. Neutralization studies indicate reduced antibody sensitivity compared to earlier Omicron subvariants, prompting its classification by WHO as a Variant Under Monitoring on 25 June 20251.

Specifications

This protein carries a polyhistidine tag at the C-terminus. The protein has a calculated MW of 138.5 kDa. The protein migrates as 80-90 kDa and 100-110 kDa when calibrated against Star Ribbon Pre-stained Protein Marker under reducing (R) condition (SDS-PAGE) .

Expression Region

Val 16 - Pro 1213

Target

Spike protein

Conjugation

Unconjugated

Tag

C-10xHis

Stability

-20°C to -70°C for 12 months in lyophilized state; -70°C for 3 months under sterile conditions after reconstitution. For long term storage, the product should be stored at lyophilized state at -20°C or lower.

Endotoxin

1.0 EU per μg

Purity

90%

Format

Powder

Buffer

0.1 M Sodium citrate, pH5.5

Molecular Weight

138.5 kDa

Additionnal Information

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Shipping Conditions

Storage Conditions

-20°C

Package Size

1mg*1

Host or Source

HEK293

Species

SARS-CoV-2

Protein ID

QHD43416.1 (T19I, R21T, T22N, A27S, S31P, S50L, V127F, G142D, F157S, R158G, K182R, R190S, L212I, V213G, L216F, H245N, A264D, I332V, G339H, R346T, K356T, S371F, S373P, S375F, T376A, R403K, D405N, R408S, K417N, N440K, K444R, V445R, G446S, N450D, L452W, L455S, F456L, N460K, S477N, T478K, N481K, E484K, F486P, N487D, Q493E, Q498R, N501Y, Y505H, E554K, A570V, T572I, D614G, P621S, H655Y, N679K, S680P, P681R, F817P, A892P, A899P, A942P, K986P, V987P, N764K, D796Y, S939F, Q954F, N969K, D1084G, P1143L)