Recombinant SEB Protein (His-tag)

Synonym

SEB, Enterotoxin type B, entB

Species

Staphylococcus aureus

Accession

P01552

Source

E.coli

SPECIFICATIONS

Amino acid sequence

Glu28-Lys266 is expressed with a 6×His tag at the N,C terminus.

Molecular Weight

Approximately 30 kDa.

Purity

>95.0% as determined by SDS-PAGE.

Endotoxin

<1.0 EU/μg of the protein by the LAL method.

Formulation

Lyophilized from sterile Tris-Hcl, pH 8.0. Normally 5%-8% trehalose and mannitol are added as protectants before lyophilization.

Reconstitution

Dissolved in sterile water, it is recommended to add 0.1% HSA or BSA for long-term preservation.

STORAGE

Stability and Storage

12 months from date of receipt at -20°C to -70°C. After reconstitution, it is stable at 4°C for 1 week or -20°C for almost 6 months (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

BACKGROUND

Staphylococcal Enterotoxin B (SEB) is an exotoxin produced by the bacterium Staphylococcus aureus. The superantigen Staphylococcal Enterotoxin B is a protein with a mass of 28.4 kDa. It is considerably more stable in non-physiological conditions than other protein-based toxins such as ricin and botulinum neurotoxins. As a bifunctional molecule, the superantigen SEB bond simultaneously with the receptor sites of Class II MHC molecules in the cell containing antigens and with the T-cell receptors (TCR) to activates the host immune system. In turn, this ternary complex activates a large number of T-lymphocytes initiating a systemic release of pro-inflammatory cytokines. Staphylococcal enterotoxins cause the intoxication staphylococcal food poisoning syndrome. The illness characterized by high fever, hypotension, diarrhea, shock, and in some cases death.

Data

SDS-PAGE

Bioactivity

Recombinant SEB Protein was determined by SDS-PAGE with Coomassie Blue.

Measured by its ability to induce TNF-alpha secretion by THP-1 cells. The ED50 for this effect is 47 μg/mL.