A major baker's asthma allergen from rye flour is considerably more active than its barley counterpart

Abstract

A rye flour protein of about 13.5 kDa, as well as its barley homologue, have been isolated. The rye component was recognized in vitro by IgE of allergic patients and provoked positive responses in 15 out of 21 baker's asthma patients (71%) when skin prick tests were performed. Its barley homologue showed no detectable in vitro reactivity and caused positive responses in only one-third of patients. Although no inhibitory activity against different a-amylases or trypsin was found for these two proteins, their N-terminal sequencing revealed considerable similarity to several members of the cereal ~x-amylase/trypsin inhibitor family.

A classification of plant food allergens☆

“…72 Allergens within the cereal superfamily of inhibitors include the glycosylated subunits of the tetrameric CM16* inhibitor from wheat 73 ; the homologous barley allergens CMb*, 73 Hor v 15 (Hor v 1/BMAI-1), 74 and barley dimeric protein 75 ; Sec c 1 from rye flour 75 ; and the rice dimeric a-amylase inhibitors RDAI-1 and RDAI-3. 76 The best characterized allergens of this group are the a-amylase inhibitors of rice grain.…”

A Multigene Family of Trypsin/α-Amylase Inhibitors from Cereals

“…Most of these inhibitors isolated from wheat, barley and rice are recognized by specific IgE when tested with sera from allergic patients (Barber et al, 1989;García-Casado et al, 1995;Gómez et al, 1990;Izumi et al, 1992;Sanchez-Monge et al, 1992;1996a,b). However, their IgE-binding capacities in vi tro are very different .…”

“…However, their IgE-binding capacities in vi tro are very different . In wheat and barley the glycosylated forms of WTAI-CM16, BTAICMb and BMAI-1 have been found to be the most prominent allergens, both in vi tro and in vivo (García-Casado et al, 1995;Sanchez-Monge et al, 1992). cDNA clones encoding these three proteins have also been isolated (García-Maroto et al, 1990;Medina et alA993;Mena et al, 1992).…”

Purification and Specificity of β1,2-Xylosyltransferase, an Enzyme That Contributes to the Allergenicity of Some Plant Proteins

“…The majority of allergies are to foods of plant origin, and a number of allergenic proteins have been identified from peanut, wheat, barley, rye, and soy (3)(4)(5)(6)(7). While linear amino acid sequences and conformational structures of proteins have been identified as IgE-binding epitopes (8), there is increasing evidence (9 -11) that specific carbohydrate structures may also be important as allergens.…”