HMGB1 isoforms | MD-2 binding | Cytokine activity | Chemokine activity |
---|
Disulfide | + | + | − |
Hg-modified | − | − | − |
Fully reduced | − | − | + |
H2S-modified | − | − | − |
Sulfonyl | − | − | − |
- Isoforms of HMGB1, generated by a synthetic formation of mercury thiolate on C106 (Hg-modified), by S-sulfhydration (H2S) to convert cysteine thiol (−SH) group to −SSH (H2S-modified), by exposure to reducing agent dithiothreitol (fully reduced) or oxidized by hydrogen peroxide (sulfonyl), were tested for their MD-2-binding via Biosensor-based surface plasmon resonance analysis (BIAcore) (3). Only disulfide HMGB1 binds to MD-2 and induced TNF secretion. Fully reduced HMGB1 has chemokine activity.