Crystallization and preliminary crystallographic analysis of human glycosylated haemoglobin

Human glycosylated haemoglobin A1C is a stable minor variant formed in vivo by post-translational modification of the main form of haemoglobin by glucose. Crystals of oxyHbA1C were obtained using the hanging-drop vapour-diffusion method and PEG as precipitant. The diffraction pattern of the crystal extends to a resolution of 2.3 A at 120 K. The crystals belong to space group C2, with unit-cell parameters a = 237.98, b = 59.27, c = 137.02 A, α = 90.00, β = 125.40, γ = 90.00°. The presence of two and a half molecules per asymmetric unit gives a crystal volume per protein weight (V M) of 9.70 A3 Da−1 and a solvent content of 49%.