<p>The 2S albumins are a group of seed storage proteins that have recently attracted considerable attention in the field of allergen science due to their allergenic potential. A new 2S albumin from seeds of <i>Nelumbo nucifera</i> (Nn-2S alb) was purified to electrophoretic homogeneity by the combination of ammonium sulfate fractionation, gel filtration, and ion exchange chromatography. The protein has a molecular mass of about 12 kDa estimated by SDS–PAGE, in good agreement with 12.5 ± 0.01 kDa determined by ESI–MS. Circular dichroism data showed that protein contained about 66% α-helices as estimated by K2D3, indicating that the protein was predominantly helical. The sedimentation coefficient (<i>s°</i><sub>20,w</sub>) of the predicted model was 1.72 ± 0.21 S. The predicted 3-dimensional structure of the Nn-2S alb revealed that the protein has a region of 12 amino acids which largely corresponds to the conserved immuno-dominant epitope of 2S allergens.</p> <p>Surface and ribbon representations of Nn-2S albumin model, showing hydrophobic cavity in gray (A), and hypervariable region (yellow in B) and the amino acids residues (sticks) that constitute hydrophobic cavity (B).</p
