Characterization of Hen Egg White- and Yolk-Riboflavin Binding Proteins and Amino Acid Sequence of Egg White-Riboflavin Binding Protein

Abstract

White- and Yolk-riboflavin binding proteins were isolated from hen eggs, and characterized as to their chemical properties. White- and Yolk-RBPs had almost same amino acid compositions except for glutamic acid, but their carbohydrate compositions were different from each other. The complete amino acid sequence of White-RBP was determined by conventional methods. White-RBP comprised 219 amino acid residues, and the amino-terminus was pyroglutamic acid (pyrrolidonecarboxylic acid). Two amino acids, lysine and asparagine, were found at the fourteenth residue from the amino-terminus. Carbohydrate chains were linked to asparagine residues at positions 36 and 147. Both White- and Yolk-RBPs were phosphorylated. In White-RBP either six or seven of nine serine residues between Ser(185) and Ser(197) were phosphorylated. The amino acid sequences around phosphoserines showed that phosphorylation might occur at a serine residue in one of the following sequences; Ser-X-Glu or Ser-X-Ser(P).

Identification of the major mannose-binding proteins from chicken egg yolk and chicken serum as immunoglobulins.

“…However, it is possible that subtle differences may exist between CS-II and CY-II that we have not as yet probed. Indeed, the carbohydrate compositions of hen serum and yolk riboflavin-binding protein were found to be different (9). Table 3 also illustrates the striking differences between the mannose-binding proteins and the liver GlcNAc-binding protein.…”

MICROSEQUENCE ANALYSIS OF N^α-BLOCKED PROTEINS ELECTROBLOTTED ONTO AN IMMOBILIZING MATRIX FROM POLYACRYLAMIDE GELS

“…Hen egg riboflavin-binding protein [5] and Geotrichum candidum lipase [6] were used as representative of proteins with a pyroglutamic acid at the N-terminus, and horse heart cytochrome c, five mutants of yeast cytochrome c [7] and bovine erythrocyte superoxide dismutase were used as representative of proteins having an N' -acetyl group at the N-terminus. Pyroglutamyl peptidase and acylamino acid-releasing enzyme were purchased from Boehringer (Mannheim , Germany) and Takara Shuzo (Kyoto, Japan), respectively.…”

Chemical Composition of Egg and Egg Products

“…Ovoflavoprotein could serve as a useful food ingredient from egg white as it is abundant as a Handbook of Food Chemistry DOI 10.1007/978-3-642-41609-5_28-1 # Canadian Crown Copyright 2014 low-cost egg processing by-product. Ovoflavoprotein binds riboflavin at pH above 4.3 with an association constant of 7.9 Â 10 8 M. It is composed of 219 amino acids (Hamazume et al 1984) with a molecular weight of 32 kDa. The carbohydrate content is about 15 %, consisting of mannose, galactose, glucosamine, and sialic acid.…”