Biophysical analysis of the interaction of the serum protein human β2GPI with bacterial lipopolysaccharide.

•β2-GPI binds more strongly to negatively charged phospatidylserine than to bacterial lipopolysaccharides (LPS).•β2-GPI has only a moderate tendency to influence LPS-induced cytokine production in vitro.•β2-GPI reacts exothermally with LPS in a non-saturable way.•β2-GPI changes its local microenvironment upon LPS association.•The serum protein β2-GPI is an immune-modulating compound.