Efficient production of Trastuzumab Fab antibody fragments in Brevibacillus choshinensis expression system

• Published in: Protein expression and purification 2018-10, Vol.150, p.109-118
• Main Authors: Mizukami, Makoto, Onishi, Hiromasa, Hanagata, Hiroshi, Miyauchi, Akira, Ito, Yuji, Tokunaga, Hiroko, Ishibashi, Matsujiro, Arakawa, Tsutomu, Tokunaga, Masao
• Format: Article
• Language: English
• Subjects: Antibody fragment; Brevibacillus choshinensis; Fab; Production; Secretion
• ISSN: 1046-5928; 1096-0279
• DOI: 10.1016/j.pep.2018.05.013

The Brevibacillus expression system has been successfully employed for the efficient productions of a variety of recombinant proteins, including enzymes, cytokines, antigens and antibody fragments. Here, we succeeded in secretory expression of Trastuzumab Fab antibody fragments using B. choshinensis/BIC (Brevibacillus in vivocloning) expression system. In the fed-batch high-density cell culture, recombinant Trastuzumab Fab with amino-terminal His-tag (His-BcFab) was secreted at high level, 1.25 g/liter, and Fab without His-tag (BcFab) at ∼145 mg/L of culture supernatant. His-BcFab and BcFab were purified to homogeneity using combination of conventional column chromatographies with a yield of 10–13%. This BcFab preparation exhibited native structure and functions evaluated by enzyme-linked immunosorbent assay, surface plasmon resonance, circular dichroism measurements and size exclusion chromatography. To our knowledge, this is the highest production of Fab antibody fragments in gram-positive bacterial expression/secretion systems. •Trastuzumab Fab was efficiently secreted in Brevibacillus/BIC expression system.•His-tag-Fab was secreted at 1.25 g and Fab at 145 mg per liter in fed-batch culture.•His-tag-Fab and Fab were purified to homogeneity using conventional chromatographies.