Expression, purification and characterization of a catalytic domain of human protein tyrosine phosphatase non-receptor 12 (PTPN12) in Escherichia coli with FKBP-type PPIase as a chaperon

- We successfully carried out the soluble expression of the catalytic domain of PTPN12 (ΔPTP-PEST) by use of FKBP_C.
- The FKBP_C can increase the percentage of soluble body and the specific activity of ΔPTP-PEST.
- The two-step chromatography procedure ensures a higher purity of ΔPTP-PEST than the traditional affinity purification.
- Our study provided a valuable expression system for ΔPTP-PEST.

Protein tyrosine phosphatase non-receptor type 12 (PTPN12), also known as PTP-PEST, was broadly expressed in hemopoietic cells. Recent research has shown that this enzyme is involved in tumorigenesis, as well as in tumor progression and transfer, as it can suppress multiple oncogenic tyrosine kinases. However, the difficulty of soluble expression of PTP-PEST in prokaryotic cells has resulted in great limitations in investigating its structure and functions. In this study, we successfully carried out soluble expression of the catalytic domain of PTP-PEST (ΔPTP-PEST) in Escherichia coli and performed an enzymatic characterization and kinetics. To confirm expression efficiency, we also induced the expression of the chaperon, FKBP_C. FKBP_C expression indicated efficacious prokaryotic expression of ΔPTP-PEST. In conclusion, our work yielded a practical expression system and two-step chromatography purification method that may serve as a valuable tool for the structural and functional analysis of proteins that are difficult to express in the soluble form in prokaryotic cells.