• Purity

  >90%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its binding ability in a functional ELISA. When recombinant human TLR-4 is Immobilized at 2 µg/mL (100 µL/well), the concentration of rhMD-2 that produces 50% optimal binding response is found to be approximately 0.03-0.15 µg/mL.

• Source

  E. coli-derived

  Met	Human MD-2 (Glu17 - Asn160) Accession # BAA78717	IEGRGGGSGGGSGGGS	10-His tag
  N-terminus			C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Met

• Predicted Molecular Mass

  19.2 kDa (monomer)

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

What formulation is right for me?

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: MD-2

MD-2, also known as lymphocyte antigen 96 and ESOP-1, is a secreted glycoprotein that shares conserved cysteine residues and significant sequence similarity (23%) with MD-1. The gene of human MD-2 encodes a 160 amino acid residue (aa) precursor protein with a 16 aa signal peptide and a 144 aa mature protein, which contains 2 N‑glycosylation sites (1). Recombinant secreted MD‑2 has been found to exist as disulfide-linked dimers and oligomers (2).

Both MD-1 and MD-2 are accessory molecules that associate with the extracellular leucine-rich repeats (LRR) of Toll-like receptor (TLR) family members, which are type I transmembrane receptors that regulate innate immune responses to microbial pathogens (3, 4). MD-1 binds to RP105 on B cells and macrophages to form the signaling receptor complex for lipopolysaccharide (LPS), a constituent of the outer membrane of Gram-negative bacteria. Similarly, MD-2 interacts with TLR-4 to form the heteromeric receptor that confers LPS responsiveness. MD-2 also associates with TLR-2, albeit with less avidity, to confer responsiveness to cell wall components from both Gram-positive and Gram-negative bacteria. MD-1 and MD-2 are also required for the correct targeting of the TLRs to the cell surface. Although MD-2 glycosylation is not crucial for its surface expression and interaction with TLR-4, it is required for LPS binding and signaling (5).

• References:

1. Shimazu, R. et al. (1999) J. Exp. Med. 189:1777.

2. Visintin, A. et al. (2001) Proc. Natl. Acad. Sci. USA 98:12156.

3. Nagai, Y. et al. (2002) Nature Immunology 3:667.

4. Akashi, S. et al. (2003) J. Exp. Med. 198:1035.

5. Correia, J. and R. Ulevitch (2002) J. Biol. Chem. 277:1845.

• Long Name:

  Myeloid Differentiation Protein 2/Lymphocyte Antigen 96

• Entrez Gene IDs:

  23643 (Human)

• Alternate Names:

  ESOP1; ESOP-1; LY96; ly-96; lymphocyte antigen 96; MD2; MD-2; myeloid differentiation protein-2; Protein MD-2