Detection by competitive enzyme-linked immunosorbent assay of a bovine serum albumin peptide (ABBOS) in infant formulas based on hydrolyzed cow's milk protein.
OBJECTIVE
Our aim was to determine whether currently available products based on hydrolyzed milk protein and a small peptide (ABBOS) in bovine serum albumin (BSA) (positions 126-144) share common antigenic sites. The commercial products are primarily developed to reduce cow's milk protein-associated allergenicity, but whether they also could be used in intervention trials to elucidate the role of BSA in the etiology of IDDM is not known.


METHODS
A sensitive competitive enzyme-linked immunosorbent assay (ELISA) using a rabbit polyclonal antibody raised against the ABBOS peptide in BSA was developed. With this method, we determined cross-reactivity between the ABBOS peptide and commercially available products: four milk protein hydrolysates and eight infant formulas based on hydrolyzed milk protein. The products were further characterized by physicochemical techniques.


RESULTS
Hydrolyzed milk protein products are found to inhibit competitively the binding of ABBOS peptide to antibody. The number of residual reactive sites varied considerably among products and was not strongly related to the degree of hydrolysis (DH) or the molecular mass distribution of the hydrolysates.


CONCLUSIONS
The presence of possible immunoreactive peptides in infant formulas based on hydrolyzed cow's milk protein cannot be adequately predicted by the DH or molecular mass distribution of the hydrolysates. Its specific determination is needed to ensure infant formulas free of cross-reactive ABBOS antibody binding sites for use in ongoing and forthcoming intervention trials to elucidate the role of BSA as a possible environmental triggering agent of IDDM.
van Beresteijn
E C
EC
Department of Nutrition, Netherlands Institute for Dairy Research (NIZO), Ede, The Netherlands.
Meijer
R J
RJ
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D002417:Cattle; D003429:Cross Reactions; D003922:Diabetes Mellitus, Type 1 / Q000209:etiology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D006868:Hydrolysis; D007074:Immunoglobulin G; D007223:Infant; D007225:Infant Food / Q000032:analysis*; D007231:Infant, Newborn; D008894:Milk Proteins; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000032:analysis* / Q000276:immunology; D011817:Rabbits; D012710:Serum Albumin, Bovine / Q000032:analysis* / Q000276:immunology
D000906:Antibodies; D007074:Immunoglobulin G; D008894:Milk Proteins; D010446:Peptide Fragments; C075490:serum albumin, bovine (152-168); D012710:Serum Albumin, Bovine