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Updated: Jan 14, 2026
High Throughput Quantitative Expression Screening and Purification Applied to Recombinant Disulfide-rich Venom Proteins Produced in E. coli
Published on: July 30, 2014
Recombinant expression and downstream processing of the disulfide-rich tumor-targeting peptide chlorotoxin
Xiao-Min Wang1, Xiao Luo, Zhan-Yun Guo
1Institute of Protein Research, College of Life Sciences and Technology, Tongji University, Shanghai 200092, P.R. China.
Abstract:
Chlorotoxin (CTX) is a scorpion-derived disulfide-rich peptide that targets malignant tumors by binding the cell surface matrix metalloproteinase-2 and annexin A2. Various CTXs labeled with functional moieties have shown great potential for tumor diagnosis and treatment. In the present study, we established an efficient approach for preparing mature CTX that may be used for experimental and therapeutic purposes. The designed CTX precursors carried either a 6xHis-tag or a 6xHis-tag and a glutathione transferase (GST)-tag and were recombinantly expressed in Escherichia coli. Following S-sulfonation, the precursors were purified using immobilized metal-ion affinity chromatography. Subsequent to the removal of the tag by enterokinase cleavage and in vitro oxidative refolding, mature CTX was obtained with a considerable yield. The yield of mature CTX whose precursors carried a 6xHis-tag and a GST-tag (2 mg per liter of culture) was ∼10-fold that of the mature CTX whose precursors carried a 6xHis-tag (150-200 μg per liter of culture). The folded CTX inhibited the migration of glioma cells in a concentration-dependent manner, suggesting it was biologically active.
Insights
Researchers developed an efficient method to produce mature chlorotoxin (CTX), a peptide targeting tumors. This advancement offers potential for improved cancer diagnosis and therapy using this biologically active compound.
Area of Science:
- Biochemistry
- Molecular Biology
- Oncology
Background:
- Chlorotoxin (CTX) is a scorpion peptide targeting cancer cells via matrix metalloproteinase-2 and annexin A2.
- Functionalized CTXs show promise for tumor diagnosis and treatment.
Purpose of the Study:
- To establish an efficient method for producing mature chlorotoxin (CTX) for experimental and therapeutic use.
- To evaluate the yield and biological activity of the produced CTX.
Main Methods:
- Recombinant expression of CTX precursors with 6xHis-tag or 6xHis-GST-tag in *Escherichia coli*.
- Purification via immobilized metal-ion affinity chromatography after S-sulfonation.
- Tag removal by enterokinase cleavage and oxidative refolding for mature CTX production.
Main Results:
- A significantly higher yield of mature CTX (2 mg/L) was achieved using the 6xHis-GST-tag precursor compared to the 6xHis-tag precursor (150-200 μg/L).
- The produced mature CTX demonstrated concentration-dependent inhibition of glioma cell migration, confirming biological activity.
Conclusions:
- An efficient recombinant expression and purification strategy for mature chlorotoxin was successfully developed.
- The enhanced yield and confirmed biological activity of CTX support its potential for future therapeutic applications in oncology.
