The hydrophobic binding pocket of MD-2 has little specificity for inhibitors, so we tried to target solvent accessible cysteine residue within the hydrophobic binding pocket of MD-2. Compounds with affinity for the hydrophobic pocket and a thiol reactive group, which forms covalent bond with free cysteine residue of MD-2 were tested. IAANS and N-pyrene maleimide formed covalent bond with MD-2 through Cys133 and inhibited LPS signaling. Cell activation was also inhibited by JTT-705 and auranofin. Oral intake of JTT-705 significantly inhibited endotoxin-triggered TNFa production in mice.
COBISS.SI-ID: 4173082
MD-2/TLR4 complex binds and responses to LPS. Despite functional similarity, human (h) and murine (m) MD-2 are different. We have determined aa residues of h and mMD-2, which are responsible for LPS binding to soluble h or mMD-2. Replacement of defined aa of mMD-2 was sufficient to yield soluble extracellular MD-2 that bound LPS and activated cells expressing TLR4 only. In contrast to wild-type mMD-2, mMD-2 mutants supported LPS signaling with hTLR4. Results show importance of Lys 122, 125, and 58 in hMD-2 in functional differences between h and m MD-2.
COBISS.SI-ID: 4227098