Identification and characterization of wheat grain albumin/globulin allergens

Abstract

Bakers' asthma, an immediate-type allergic response to the inhalation of cereal flours, is an important occupational disease among workers of the baking and milling industries, and the salt-soluble proteins of wheat and rye flour dust are considered the most relevant allergens. In order to identify and characterize the major IgE-binding proteins, the polypeptide composition of the albumin/globulin protein fraction obtained from different cultivars was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and high-resolution two-dimensional polyacrylamide gel electrophoresis with immobilized pH gradients in the first dimension (IPG-Dalt), followed by immunoblotting with sera from asthmatic bakers. Relevant allergens were isolated by micropreparative IPG-Dalt and blotting onto polyvinylidenedifluoride membranes and identified by amino acid composition analysis or N-terminal amino acid sequence analysis. SDS-PAGE, IPG-Dalt, and immunoblotting demonstrated that the sera of the bakers allergic to flour contained IgE antibodies which bound to numerous albumin/globulin polypeptides in the 70, 55, 35, 26-28, and 14-18 kDa areas. More detailed investigations using IPG-Dalt revealed cultivar-specific differences in IgE-binding. It was also demonstrated that the majority of the allergens were not single polypeptide spots, but consisted of up to ten isoforms of similar molecular mass but different isoelectric points. Amino acid composition analysis and N-terminal amino acid sequence analysis, which were performed for nine allergens located in the 14-18, 26-28, and 35 kDa areas, revealed homologies to amylase/protease inhibitors, acyl-CoA oxidase and fructose-bisphosphate-aldolase from wheat, barley, maize, and rice, respectively.

IgE-binding Abilities of Pentapeptides, QQPFP and PQQPF, in Wheat Gliadin

“…Among them, alpha-amylase inhibitors (AI) from globulin fraction were identified as major allergens (3)(4)(5)(6). Acyl-CoA oxidase (7,8), peroxi dase (9), and fructose-bisphosphate aldolase (8) were identified as other allergens.…”

Influence of glycation and pepsin hydrolysis on immunoreactivity of albumin/globulin fraction of herbicide resistant wheat line

“…Their molecular weights were about 14.2, 36, and 66 kDa with another one having a molecular weight higher than the standards used. According to the literature (Weiss et al 1997;Mittag et al 2004), those fractions represent the main immunoreactive proteins in albumin/globulin fractions.…”

Molecular and Immunological Characterization of a Wheat Serine Proteinase Inhibitor as a Novel Allergen in Baker's Asthma

“…The disease is mainly caused by allergens present in wheat flour. Some of these allergens, such as fungal ␣-amylase, are derived from contaminants or additives (41), whereas others represent genuine wheat proteins or glycoproteins (18,22,23,42). At present, only few genuine wheat allergens have been identified, and it is not yet clear whether they are specific for baker's asthma or whether they are also recognized by patients suffering from wheat-associated food allergy or grass pollen allergy (26).…”