Binding and biologic characterization of recombinant human serum albumin-eTGFBR2 fusion protein expressed in CHO cells. Issue 5 (3rd September 2017)

• Record Type: Journal Article
• Authors: Wan, Aini; Miao, Yana; Peng, Lin; Cai, Yanfei; Chen, Yun; He, Yang; Yang, Jianfeng; Jin, Jian; Li, Huazhong
• Is Part Of: Bioengineered. Volume 8:Issue 5(2017)
• Page Start: 600
• Page End: 612
• Publication Date: 2017-09-03
• Subjects: Antagonist -- Chinese hamster ovary cells -- eTGFBR2 -- human serum albumin -- TGF-β1; Biomedical engineering -- Periodicals; Biotechnology -- Periodicals; Microbiology -- Periodicals; 660.6
• DOI: 10.1080/21655979.2017.1292186
• Languages: English
• ISSNs: 2165-5987

Abstract

ABSTRACT: Transforming growth factor-β1 (TGF-β1) signaling is involved in cell metabolism, growth, differentiation, carcinoma invasion and fibrosis development, which suggests TGF-β1 can be treated as a therapeutic target extensively. Because TGF-β1 receptor type α(TGFBR2) is the directed and essential mediator for TGF-β1 signals, the extracellular domain of TGFBR2 (eTGFBR2), binding partner for TGF-β1, has been produced in a series of expression systems to inhibit TGF-β1 signaling. However, eTGFBR2 is unstable with a short half-life predominantly because of enzymatic degradation and kidney clearance. In this study, a fusion protein consisting of human eTGFBR2 fused at the C-terminal of human serum albumin (HSA) was stably and highly expressed in Chinese Hamster Ovary (CHO) cells. The high and stable expression sub-clones with Ig kappa signal peptide were selected by Western blot analysis and used for suspension culture. After fed-batch culture over 8 d, the expression level of HSA-eTGFBR2 reached 180 mg/L. The fusion protein was then purified from culture medium using a 2-step chromatographic procedure that resulted in 39% recovery rate. The TGF-β1 binding assay revealed that HSA-eTGFBR2 could bind to TGF-β1 with the affinity constant (KD of 1.42 × 10 −8 M) as determined by the ForteBio Octet System. In addition, our data suggested that HSA-eTGFBR2 exhibited a TGF-β1 neutralizing activity and maintained a long-term activity more than eTGFBR2. It concluded that the overexpressing CHO cell line supplied sufficient recombinant human HSA-eTGFBR2 for further research and other applications.