Purification, crystallization and preliminary X-ray analysis of the ligand-binding domain of human lectin-like oxidized low-density lipoprotein receptor 1 (LOX-1)

Abstract

Two different fragments of the ligand-binding domain of LOX-1, the major receptor for oxidized low-density lipoprotein (LDL) on endothelial cells, have been crystallized in different forms. One crystal form contains the disulfide-linked dimer, which is the form of the molecule present on the cell surface; the other contains a monomeric form of the receptor that lacks the cysteine residue necessary to form disulfide-linked homodimers. The crystal of the monomeric ligand-binding domain belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 56.79, b = 67.57, c = 79.02 A. The crystal of the dimeric form belongs to space group C2, with unit-cell parameters a = 70.86, b = 49.56, c = 76.73 A, beta = 98.59 degrees. Data for the dimeric form of the LOX-1 ligand-binding domain have been collected to 2.4 A. For the monomeric form of the ligand-binding domain, native, heavy-atom derivative and SeMet-derivative crystals have been obtained; their diffraction data have been measured to 3.0, 2.4 and 1.8 A resolution, respectively.