Soybean P34

Soybean (Glycine max) is a major source of edible oil and protein, widely used in human and animal nutrition. However, it contains several allergenic proteins that can cause allergic reactions in sensitive individuals. One of the major allergenic proteins in soybean is the P34 protein, also known as Gly m Bd 30K or Gly m 1 .

The P34 protein is a monomeric insoluble glycoprotein with an isoelectric point of 4.5 and an amino acid-based calculated mass of 28.643 Da . In its glycosylated form, the mass is slightly larger, resulting in a band of approximately 32 kDa in non-reduced SDS PAGE gels . P34 belongs to the papain family of thiol proteases and has an N-terminal amino acid sequence and composition identical to that of the seed 34kDa protein .

P34 is recognized as the main allergen for soybean-sensitive humans . The incidence of adverse reactions to food antigens, including P34, is particularly high in children, ranging from 2-8%, compared to 1-2% in adults . The allergenic potential of P34 necessitates detailed studies to understand how food antigens reach immune cells and elicit allergic reactions.

Recombinant P34 protein is a valuable tool for analyzing antigen-specific responses in soybean allergy . It can be used in various applications, including the development of diagnostic methods and specific immunotherapy techniques for soybean allergy .

Recent studies have identified molecular mechanisms controlling P34 gene expression in soybean. For instance, two low-P34 soybean accessions, PI603570A and PI567476, were identified . Comparative analysis of P34 cDNAs and genomic sequences from low-P34 and normal soybean accessions revealed that genetic polymorphisms in P34 promoters significantly affect translation efficiency . Specifically, a 4-bp insertion in front of the start codon of the P34 gene in PI567476 leads to reduced translation efficiency and lower accumulation of P34 protein .

A method for purifying soybean P34 protein using hydrophobic interaction chromatography has been developed . This technique allows for the production of pure P34 protein within a short timeframe, suitable for further studies where an example antigen is needed . The purification process involves using Butyl Sepharose 4 FF as the stationary phase and ammonium sulfate for gradient elution .