Complex assembly, crystallization and preliminary X-ray crystallographic analysis of the chicken CD8αα–BF2*0401 complex

In the process of antigen presentation, the MHCI–CD8 complex is important for immune signal transduction by the activation of cytotoxic T cells. Here, the expression, purification, crystallization and X-ray analysis of the complex of the chicken MHC class I molecule BF2*0401 and CD8αα (CD8αα–BF2*0401) are reported. This complex was verified by SDS–PAGE analysis of a CD8αα–BF2*0401 crystal, which showed three bands corresponding to the molecular weights of BF2*0401, β₂-microglobulin and CD8α, respectively. The crystal of CD8αα–BF2*0401 diffracted to 2.8 Å resolution and belonged to space group P2₁, with unit-cell parameters a = 90.6, b = 90.8, c = 94.9 Å, β = 98°. The Matthews coefficient and solvent content were calculated to be 2.88 ų Da⁻¹ and ∼57.3%, respectively.