Purification crystallization and preliminary X-ray diffraction studies on human Ca2+-binding protein S100B

摘要

S100B, a Ca²⁺-binding protein, acts intracellularly as a Ca²⁺-signalling protein but is also secreted to the extracellular space, acting in a cytokine-like manner through its receptor RAGE. Recombinant human S100B has been purified and crystallized in the Ca²⁺-bound state. Size-exclusion chromatography indicates that S100B can exist as a dimer and as a multimer in solution. Crystals of S100B diffract to 1.9 Å and belong to space group P21, with unit-cell parameters a = 63.4, b = 81.6, c = 71.5 Å, α = 90, β = 107, γ = 90°. Preliminary analysis of the X-ray data indicate that there are four homodimers per asymmetric unit.