National Technology Innovation Center of Synthetic Biology, Key Laboratory of Engineering Biology for Low-Carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
Key Laboratory for Molecular Enzymology and Engineering, The Ministry of Education, School of Life Science, Jilin University, Changchun 130012, China.
Int J Mol Sci. 2023 Jun 22;24(13):10475. doi: 10.3390/ijms241310475.
SARS-CoV-2 relies on the recognition of the spike protein by the host cell receptor ACE2 for cellular entry. In this process, transmembrane serine protease 2 (TMPRSS2) plays a pivotal role, as it acts as the principal priming agent catalyzing spike protein cleavage to initiate the fusion of the cell membrane with the virus. Thus, TMPRSS2 is an ideal pharmacological target for COVID-19 therapy development, and the effective production of high-quality TMPRSS2 protein is essential for basic and pharmacological research. Unfortunately, as a mammalian-originated protein, TMPRSS2 could not be solubly expressed in the prokaryotic system. In this study, we applied different protein engineering methods and found that an artificial protein XXA derived from an antifreeze protein can effectively promote the proper folding of TMPRSS2, leading to a significant improvement in the yield of its soluble form. Our study also showed that the fused XXA protein did not influence the enzymatic catalytic activity; instead, it greatly enhanced TMPRSS2's thermostability. Therefore, our strategy for increasing TMPRSS2 expression would be beneficial for the large-scale production of this stable enzyme, which would accelerate aniti-SARS-CoV-2 therapeutics development.
SARS-CoV-2 依靠其刺突蛋白与宿主细胞受体 ACE2 的识别来实现细胞进入。在这个过程中，跨膜丝氨酸蛋白酶 2（TMPRSS2）起着关键作用，因为它作为主要的引发剂，催化刺突蛋白切割，启动细胞膜与病毒融合。因此，TMPRSS2 是 COVID-19 治疗开发的理想药理学靶点，有效生产高质量的 TMPRSS2 蛋白对于基础和药理学研究至关重要。不幸的是，由于 TMPRSS2 是一种哺乳动物起源的蛋白，因此不能在原核系统中可溶表达。在这项研究中，我们应用了不同的蛋白质工程方法，发现一种源自抗冻蛋白的人工蛋白 XXA 可以有效地促进 TMPRSS2 的正确折叠，从而显著提高其可溶形式的产量。我们的研究还表明，融合的 XXA 蛋白不会影响酶的催化活性，反而大大提高了 TMPRSS2 的热稳定性。因此，我们提高 TMPRSS2 表达的策略将有利于这种稳定酶的大规模生产，从而加速抗 SARS-CoV-2 治疗的开发。
