Identification of Novel IgE-binding Soybean Allergens Using Serological Analysis of a Recombinant cDNA Expression Library (SEREX)

New immunoglobulin E (IgE)-binding proteins from soybean (Glycine max L.) were identified using serological analysis of a recombinant cDNA expression library (SEREX) derived from soybean seeds and an enzyme-linked immunosorbent assay (ELISA). A soybean cDNA expression library was synthesized using the lambda ZAP express phage vector system and screened using sera of soybean-sensitive patients with atopic dermatitis (AD). A total of 3 new IgE-binding soybean proteins were identified as enolase, triosephosphate isomerase (TPI), and malate dehydrogenase (MDH). Full-length cDNAs were cloned into the expression vector pET15b, and expressed in Escherichia coli BL21 (DE3). The recombinant proteins were purified using affinity chromatography, followed by ELISA, with the sera of AD patients, resulting in positive reactions. The cDNA sequences were submitted to the GenBank Nucleotide Sequence Database with the accession numbers AY496909 (enolase), AY631048 (TPI), and AY496910 (MDH).