Structural and Physicochemical Characteristics of Novel Basic Proteins Isolated from Duck Egg White

Supaporn NAKNUKOOL, Shigeru HAYAKAWA, Yuanxia SUN, Masahiro OGAWA
2008 Bioscience, biotechnology and biochemistry  
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.
more » ... 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 () proteins. Both dBPS 1 and dBPS 2 , possessed high heat stability, Td 101.2 and 98.3 C. Indirect ELISA results showed that the dBPS 1 /dBPS 2 -related proteins were distributed in the oviduct and gallbladder.
doi:10.1271/bbb.80178 pmid:18685220 fatcat:vgltsjxmhzdylkll5ygypbfesy