title: Use of NaCl prevents aggregation of recombinant COMP-angiopoietin-1 in Chinese hamster ovary cells.
abstract: To investigate the effect of hyperosmotic medium on production and aggregation of the variant of Angiopoietin-1 (Ang1), cartilage oligomeric matrix protein (COMP)-Ang1, in recombinant Chinese hamster ovary (CHO) cells, CHO cells were cultivated in shaking flasks. NaCl and/or sorbitol were used to raise medium osmolality in the range of 300-450mOsm/kg. The specific productivity of COMP-Ang1, q(COMP-Ang1), increased as medium osmolality increased. At NaCl-450mOsm/kg, the q(COMP-Ang1) was 7.7-fold higher than that at NaCl-300mOsm/kg, while, at sorbitol-450mOsm/kg, it was 2.9-fold higher than that at sorbitol-300mOsm/kg. This can be attributed to the increased relative mRNA level of COMP-Ang1 at NaCl-450mOsm/kg which was approximately 2.4-fold higher than that at sorbitol-450mOsm/kg. Western blot analysis showed that COMP-Ang1 aggregates started to occur in the late-exponential phase of cell growth. When sorbitol was used to raise the medium osmolality, a severe aggregation of COMP-Ang1 was observed. On the other hand, when NaCl was used, the aggregation of COMP-Ang1 was drastically reduced at NaCl-400mOsm/kg. At NaCl-450mOsm/kg, the aggregation of COMP-Ang1 was hardly observed. This suggests that environmental conditions are critical for the aggregation of COMP-Ang1. Taken together, the use of NaCl-induced hyperosmotic medium to cell culture process turns out to be an efficient strategy for enhancing COMP-Ang1 production and reducing COMP-Ang1 aggregation.
authors: Bio R&D Center, Genexel-Sein, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701, Republic of Korea.
authors: Hye Kyung
authors: HK
authors: Ju
authors: Su-Jeong
authors: SJ
authors: Hwang
authors: Choon-Ju
authors: CJ
authors: Jeon
authors: Gyun Min
authors: GM
authors: Lee
authors: Sung Kwan
authors: SK
authors: Yoon
mesh_terms: D000818:Animals; D015153:Blotting, Western; D016466:CHO Cells; D049109:Cell Proliferation; D002470:Cell Survival; D006224:Cricetinae; D003412:Cricetulus; D003470:Culture Media; D009994:Osmolar Concentration; D016133:Polymerase Chain Reaction; D055503:Protein Multimerization; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D012965:Sodium Chloride / Q000494:pharmacology*; D013012:Sorbitol / Q000378:metabolism
chemical_list: C515576:COMP-Ang1 fusion protein; D003470:Culture Media; D011993:Recombinant Fusion Proteins; D012965:Sodium Chloride; D013012:Sorbitol