title: Purification and characterization of 2S albumin from Nelumbo nucifera.
abstract: 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 Nelumbo nucifera (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 (s°20,w) 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.
authors.affiliation: a Department of Biosciences, COMSATS Institute of Information Technology , Islamabad , Pakistan.
authors.forename: Sanaullah
authors.initials: S
authors.lastname: Khan
authors.affiliation: b International Center for Chemical and Biological Sciences, HEJ Research Institute of Chemistry , University of Karachi , Karachi , Pakistan.
authors.forename: Syed Abid
authors.initials: SA
authors.lastname: Ali
authors.affiliation: a Department of Biosciences, COMSATS Institute of Information Technology , Islamabad , Pakistan.
authors.forename: Tayyaba
authors.initials: T
authors.lastname: Yasmin
authors.affiliation: c Department of Biotechnology , University of Science and Technology , Bannu , Pakistan.
authors.forename: Mushtaq
authors.initials: M
authors.lastname: Ahmed
authors.affiliation: d Department of Chemistry, University of Science and Technology , Bannu , Pakistan.
authors.forename: Hidayatullah
authors.initials: H
authors.lastname: Khan
keywords: 2S albumins; CD spectroscopy; N-terminal amino acid sequence; homology modeling; purification