High-level accumulation of a recombinant antibody fragment in the periplasm of Escherichia coli requires a triple-mutant (degP prc spr) host strain

• Published in: Biotechnology and bioengineering 2004-03, Vol.85 (5), p.463-474
• Main Authors: Chen, Christina, Snedecor, Brad, Nishihara, Julie C., Joly, John C., McFarland, Nancy, Andersen, Dana C., Battersby, John E., Champion, Kathleen M.
• Format: Article
• Language: English
• Subjects: Antibodies; Biological and medical sciences; biopharmaceutical; Biotechnology; CD18 Antigens - immunology; Cell Culture Techniques - methods; Cell density; Cell Division; Cell Survival; Endopeptidases - genetics; Endopeptidases - metabolism; Escherichia coli; Escherichia coli - cytology; Escherichia coli - genetics; Escherichia coli - growth & development; Escherichia coli - metabolism; Fermentation; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Bacterial - physiology; Health. Pharmaceutical industry; Heat-Shock Proteins - genetics; Heat-Shock Proteins - metabolism; high cell density fermentation; Immunoglobulin Fragments - biosynthesis; Immunoglobulin Fragments - chemistry; Immunoglobulin Fragments - genetics; Immunoglobulin Fragments - immunology; Industrial applications and implications. Economical aspects; Light chains; Monoclonal antibodies; Mutagenesis, Site-Directed; Periplasm - metabolism; periplasmic protease; Periplasmic Proteins - genetics; Periplasmic Proteins - metabolism; Production of active biomolecules; Protein Engineering - methods; Proteinase; Proteolysis; Q1; Q2; recombinant antibody; Recombinant Proteins - biosynthesis; Serine Endopeptidases - genetics; Serine Endopeptidases - metabolism; Species Specificity; spr gene; two-dimensional gel electrophoresis
• ISSN: 0006-3592; 1097-0290
• DOI: 10.1002/bit.20014

During production of a humanized antibody fragment secreted into the periplasm of Escherichia coli, proteolytic degradation of the light chain was observed. In order to determine which protease(s) were responsible for this degradation, we compared expression of the F(ab′)2 antibody fragment in several E. coli strains carrying mutations in genes encoding periplasmic proteases. Analysis of strains cultured in high cell density fermentations showed that the combination of mutations in degP prc spr was necessary for the cells to produce high levels of the desired recombinant antibody fragment. In order to eliminate the possible effects of mutations in other genes, we constructed E. coli strains with protease mutations in isogenic backgrounds and repeated the studies in high cell density fermentations. Extensive light chain proteolysis persisted in degP strains. However, light chain proteolysis was substantially decreased in prc and prc spr strains, and was further decreased with the introduction of a degP mutation in prc and prc spr mutant strains. These results show that the periplasmic protease Prc (Tsp) is primarily responsible for proteolytic degradation of the light chain during expression of a recombinant antibody fragment in E. coli, and that DegP (HtrA) makes a minor contribution to this degradation as well. The results also show that spr, a suppressor of growth defects in prc strains, is required for a prc mutant to survive throughout high cell density fermentations. © 2004 Wiley Periodicals, Inc.