Exploring the chicken egg white proteome with combinatorial peptide ligand libraries.
The use of two types of peptide ligand libraries (PLL), containing hexapeptides terminating either with a primary amine or modified with a terminal carboxyl group, allowed the discovery and identification of a large number of previously unreported egg white proteins. Whereas the most comprehensive list up to date ( Mann, K. , Proteomics 2007, 7, 3558- 3568 ) tabulated 78 unique gene products, our findings have almost doubled that value to 148 unique protein species. From the initial nontreated egg, it was possible to find 41 protein species; the difference (107 proteins) was generated as a result of the use of PLLs from which a similar number of species (112 and 109, respectively) was evidenced. Of those, 35 proteins were the specific catch of the amino-terminus PLL, while 33 were uniquely captured by the carboxy-terminus PLL. While a number of these low-abundance proteins might have a biological role in maintaining the integrity of the egg white and protecting the yolk, others might be derived from decaying epithelial cells lining the oviduct and/or represent remnants of products from the magnum and eggshell membrane components secreted by the isthmus, which might ultimately be incorporated, even if in trace amounts, into the egg white. The list of egg white components here reported is by far the most comprehensive at present and could serve as a starting point for isolation and functional characterization of proteins possibly having novel pharmaceutical and biomedical applications.
Proteomics & Mass Spectrometry Laboratory, ISPAAM, National Research Council, Naples, Italy.
Chiara
C
D'Ambrosio
Simona
S
Arena
Andrea
A
Scaloni
Luc
L
Guerrier
Egisto
E
Boschetti
Martha Elena
ME
Mendieta
Attilio
A
Citterio
Pier Giorgio
PG
Righetti
D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D004527:Egg Proteins / Q000032:analysis*; D004529:Egg White / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D019151:Peptide Library; D020543:Proteome / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D004527:Egg Proteins; D019151:Peptide Library; D020543:Proteome