title: Structural and physicochemical characteristics of novel basic proteins isolated from duck egg white.
abstract: Novel basic proteins, duck basic protein small 1 (dBPS(1)) and 2 (dBPS(2)), were isolated from duck egg white by cation-exchange and gel filtration chromatography. Protein sequence analyses indicated that they possessed 39 amino acid residues with three disulfide bonds. The amino acid sequence of dBPS(1) showed 45% identity with dBPS(2). The amino acid sequence of dBPS(2) was the same as cygnin, a small protein from black swan, and strongly homologous with meleagrin from turkey and chicken. Phylogenic relationships implied that dBPS(1) and dBPS(2) share a common ancestry with cygnin and meleagrin. Based on MALDI-TOF mass spectra, the molecular masses of dBPS(1) and dBPS(2) were 4,373, and the 4,486 Da. pI of dBPS(1) and dBPS(2) elucidated by isoelectric focusing were 9.35 and 9.44. FT-IR spectra classified these proteins as (beta) proteins. Both dBPS(1) and dBPS(2), possessed high heat stability, Td 101.2 and 98.3 degrees C. Indirect ELISA results showed that the dBPS(1)/dBPS(2)-related proteins were distributed in the oviduct and gallbladder.
authors.affiliation: Department of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki, Japan.
authors.forename: Supaporn
authors.initials: S
authors.lastname: Naknukool
authors.forename: Shigeru
authors.initials: S
authors.lastname: Hayakawa
authors.forename: Yuanxia
authors.initials: Y
authors.lastname: Sun
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ogawa
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002152:Calorimetry, Differential Scanning; D002850:Chromatography, Gel; D004220:Disulfides / Q000737:chemistry / Q000378:metabolism; D004372:Ducks; D004529:Egg White / Q000737:chemistry*; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010802:Phylogeny; D011489:Protein Denaturation; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D004220:Disulfides; D011506:Proteins