Turkish Journal of Chemistry
Abstract
The human epidermal growth factor receptor 2 tyrosine kinase domain (HER2-TKD) is an important therapeutic target in oncology. In this study, we developed a practical and cost-effective approach for producing soluble recombinant HER2-TKD in Escherichia coli as a basis for structure-based drug discovery. The gene encoding HER2-TKD was cloned into a pET28a(+) expression vector and expressed in E. coli. Since the protein was initially obtained as inclusion bodies, solubilization with 1.5% sarcosyl was applied to recover it in soluble form. The purified protein was obtained through size-exclusion chromatography, followed by tag removal using reverse affinity purification. Crystallization trials were performed under more than 3000 conditions with commercial screening kits. Although most of the early crystals turned out to be salts rather than protein crystals, these observations underline the inherent challenges of HER2-TKD crystallization and highlight areas for further optimization. Overall, we establish a reproducible expression and purification workflow for HER2-TKD and provide a foundation for future cocrystallization experiments with small-molecule inhibitors and applications in structure-based drug screening.
Author ORCID Identifier
EDANUR TOPALAN: 0009-0009-0532-020X
HALİLİBRAHİM ÇİFTÇİ: 0000-0002-9796-7669
HASAN DEMİRCİ: 0000-0002-9135-5397
DOI
10.55730/1300-0527.3794
Keywords
HER2-TKD, soluble expression, sarcosyl, inclusion bodies, protein crystallization, Escherichia coli
First Page
231
Last Page
242
Publisher
The Scientific and Technological Research Council of Türkiye (TÜBİTAK)
Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.
Recommended Citation
TOPALAN, E, ÇİFTÇİ, H, & DEMİRCİ, H (2026). Production, purification, and crystallization of the recombinant HER2 tyrosine kinase domain (HER2-TKD). Turkish Journal of Chemistry 50 (3): 231-242. https://doi.org/10.55730/1300-0527.3794