Expression, purification, and immunological characterization of Cr PI

Area of Science:

• Biochemistry
• Molecular Biology
• Allergen Production

Background:

• Cockroach allergy is a significant health concern.
• Periplaneta americana nymphae allergen, Cr PI, is a key allergen.
• Efficient and large-scale production of allergens is crucial for diagnostics and therapeutics.

Purpose of the Study:

• To develop an efficient method for preparing Periplaneta americana nymphae allergen, Cr PI.
• To optimize the expression, refolding, and purification of recombinant Cr PI (rCr PI).
• To confirm the allergenic potential of the purified rCr PI.

Main Methods:

• Recombinant expression of Cr PI as a GST-tag fusion protein in Escherichia coli.
• Optimization of protein expression, denaturation/renaturation, and inclusion body aggregation.
• Purification using affinity and size exclusion chromatography.
• Confirmation of IgE binding using Western blot and ELISA.

Main Results:

• Successfully expressed and purified recombinant Cr PI (rCr PI) to >95% purity.
• Optimized conditions for refolding inclusion bodies and L-arginine concentration.
• Demonstrated strong binding of rCr PI to IgE from cockroach-allergic individuals' sera.
• Obtained highly refolded and purified recombinant allergen.

Conclusions:

• An efficient protocol for large-scale preparation of Cr PI allergen was established.
• The purified recombinant Cr PI is immunologically active and binds to IgE.
• This work provides a foundation for developing improved diagnostics and therapies for cockroach allergy.