MD-2 exists as a cell surface protein in association with TLR4. It also exists as secreted forms consisting of MD-2 monomer and multimers. Circulating sMD-2 is mainly present as a doublet of ~20 and 25 kD, representing differentially glycosylated forms. Unlike TLR4, sMD-2 binds directly LPS without the need of soluble CD14 (sCD14). However, LPS-MD-2 interactions are increased when LPS is pretreated with CD14. Only monomeric sMD-2 is biologically active and able to associate with TLR4 and LPS. sMD-2 circulates in plasma of healthy individuals as a non-active, polymeric protein. In septic plasma, the total amount of sMD-2 was strongly elevated and contained both sMD-2 polymers and monomers. Soluble MD-2 is proposed to be an important mediator of organ inflammation during sepsis. During experimental human endotoxemia, the monomeric and total sMD-2 content in plasma increased with the kinetics of an acute phase protein. This parallels enhanced TLR4 costimulatory activity. In vitro studies revealed that sMD-2 release appears to be restricted to endothelial and dendritic cells.
The monoclonal antibody 4H1 reacts with both the monomeric and the polymeric form of sMD-2. In addition, the monoclonal antibody 4H1 is able to inhibit LPS binding to MD-2.It does not cross-react with mouse MD-2.| Cross reactant | Reactivity |
| Human | Yes |
| HM2243F | sMD-2 and sMD-2/TLR4, Human, mAb 4H1, FITC |
| HM2244 | sMD-2, human, mAb 10D5 |
| HM2245 | MD-2, Human, mAb 18H10 |
| HM2246 | TLR4/MD-2, Human, mAb 7E3 |
|
Cat. No. |
Product |
MD-2 |
sMD-2 |
MD-2/TLR4 complex |
Inhibition of biological activity |
Other applications |
|
sMD-2 and sMD-2/TLR4, human, mAb 4H1 |
+ |
+ |
+ |
+ |
IA IF W |
|
|
HM2244 |
sMD-2, human, mAb 10D5 |
- |
+ |
- |
- |
IA IF W |
|
MD-2, human, mAb 18H10 |
+ |
- |
+ |
+ |
FC |
|
|
HM2246 |
TLR4/MD-2, human, mAb 7E3 |
- |
- |
+ |
+ |
FC |
| Related products | Cat # | |
|---|---|---|
| sMD-2, human, mAb 10D5 | HM2244 | |
| TLR4/MD-2, Human, mAb 7E3 | HM2246 | |
| MD-2, Human, mAb 18H10 | HM2245 | |