Soybean P34 GST

The Soybean P34 protein is a significant allergen for individuals sensitive to soybeans. It belongs to the papain family of thiol proteases and is a monomeric allergen. The P34 protein is characterized by its N-terminal amino acid sequence and composition, which is identical to that of the seed 34kDa protein. It is an insoluble glycoprotein with a pI of 4.5 and a calculated mass of 28.643 Daltons. Upon glycosylation, the mass increases, resulting in a ~32kDa band in non-reduced SDS PAGE gels .

The recombinant P34 protein fused to a GST (Glutathione S-transferase) tag is expressed in Escherichia coli (E. coli). The GST tag facilitates the purification process, allowing the recombinant protein to be isolated using glutathione affinity chromatography. The recombinant protein contains epitopes 214-261 and 351-379 amino acids of the Soybean P34 protein .

The purification process involves proprietary chromatographic techniques, ensuring that the protein is more than 95% pure as determined by 10% PAGE (Coomassie staining) and RP-HPLC . The final formulation typically includes 50mM Tris-HCl (pH 8.0), 60mM NaCl, 10mM glutathione, and 50% glycerol .

The P34 protein, despite being a thiol protease, exhibits no enzymatic function due to the absence of the catalytic cysteine. This characteristic makes it an interesting subject for allergenicity studies rather than enzymatic activity analysis . The GST tag not only aids in purification but also enhances the solubility of the recombinant protein, making it suitable for various laboratory research applications .

The recombinant Soybean P34 protein with a GST tag is stable at 4°C for up to one week but should be stored below -18°C for long-term storage to prevent freeze-thaw cycles . This ensures the protein maintains its integrity and functionality for research purposes.

The recombinant Soybean P34 protein is primarily used in laboratory research, particularly in studies related to allergenicity and immunization protocols. It is ideal for generating antibodies that specifically target the P34 protein, aiding in the development of diagnostic tools and therapeutic interventions .