On 23 September, at VNUHCM–University of Science, Researcher Lê Dương Vương (cohort 2018) successfully defended his doctoral thesis in Microbiology entitled “Production of TEV and HRV3C Proteases in Bacillus subtilis for Removing Fusion Tags in Recombinant Protein Purification”, under the supervision of Assoc. Prof. Nguyễn Đức Hoàng and Assoc. Prof. Phan Thị Phượng Trang.

Tobacco Etch Virus (TEV) protease and Human Rhinovirus 3C (HRV3C) protease are widely used tools for removing fusion tags during recombinant protein purification. However, most studies to date have focused on expression in Escherichia coli, a system that poses limitations due to endotoxin contamination, resulting in additional processing costs and time.

To address this issue, the thesis utilised Bacillus subtilis – a safe expression host free of endotoxins – to generate and purify three proteases (His-TEV, His-HRV3C, His-GST-HRV3C). The study also developed GFP-based fusion protein substrates containing specific cleavage sites, enabling assessment of protease activity and kinetic parameters. Results confirmed the potential application of these proteases in recombinant protein purification, offering a more cost-effective and efficient production method.

The dissertation successfully cloned and purified the three proteases from B. subtilis, achieving activity levels comparable to commercial enzymes expressed in E. coli. In addition, expression plasmids for GFP-based substrates containing TEV/HRV3C cleavage sites were constructed, enabling precise activity and kinetic characterisation. The findings demonstrate that the proteases can be effectively applied to target recombinant protein purification.

Members of the Thesis Committee evaluating the doctoral dissertation of Researcher Vương.

These results open new directions for developing safe and cost-effective methods for recombinant protein purification, with potential applications in industry, agriculture, and medicine. In the future, optimising expression conditions in B. subtilis may improve yields, advancing towards large-scale production as an alternative to E. coli-based systems.

The thesis demonstrates not only the researcher’s capacity for independent research and critical scientific thinking, but also the quality of doctoral training at VNUHCM–University of Science. This successful defence lays the foundation for further studies on optimising Bacillus subtilis-expressed enzymes and contributes to the training of highly qualified human resources in biology and biotechnology.

For the full abstract of the thesis, please refer to the official page: https://sdh.hcmus.edu.vn/2025/08/04/trang-thong-tin-gioi-thieu-luan-an-tien-si-cua-ncs-le-duong-vuong/