Heat-inducible surface stress protein (Hsp70) mediates sulfatide recognition of the respiratory pathogen Haemophilus influenzae

The in vitro glycolipid binding specificity of clinical strains of nontypea ble Haemophilus influenzae is altered to include sulfated glycolipids follo wing a brief heat shock. We have constructed, expressed, and purified a rec ombinant protein of H, influenzae Hsp70, which showed significant specific binding to sulfated galactolipids in vitro. Furthermore, indirect immunoflu orescence demonstrates that Hsp70 proteins are surface exposed in H, influe nzae only after heat shock and are contained in the outer membrane protein fractions.