Binding of glycoprotein β2-GPI with oxidized low density lipoprotein

Abstract:

We analyzed the binding of P.rβ2-GPI-DV with ox-LDL by fluorescence, molecular simulation and circular dichroism. We used SDS-PAGE and Western blotting to identify the purity of P.rβ2-GPI-DV, fluorescence, circular dichroism spectroscopy and molecular docking simulation to analyze the binding between P.rβ2-GPI-DV and oxLDL. P.rβ2-GPI-DV was specifically recognized by anti-His antibody at 12 kDa position. The chromophoric groups, the changes of secondary structure and the molecular docking simulations revealed that the active pocket formed by Cys281-Lys-Asn-Lys-Glu-Lys-Lys287 and Leu313-Ala-Phe-Trp316 of P.rβ2-GPI-DV and the -COOH carboxyl of oxLig-1 were the key for binding. P.rβ2-GPI combined with ox-LDL via the fifth functional domain and the -COOH group. Our findings provide theoretical basis to further study the binding between β2-GPI and ox-LDL in serum.

Key words:β2-glycoprotein I, recombinant fifth domain of β2-glycoprotein I, oxidized low density lipoprotein, 7-ketocholesteryl-9-carboxynonanoate ligand, binding mechanism