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Glycosylation of CHO‐Derived Recombinant tPA Produced under Elevated pCO 2
Author(s) -
Kimura Roy,
Miller William M.
Publication year - 1997
Publication title -
biotechnology progress
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 129
eISSN - 1520-6033
pISSN - 8756-7938
DOI - 10.1021/bp9700162
Subject(s) - chinese hamster ovary cell , sialic acid , glycosylation , monosaccharide , chemistry , biochemistry , recombinant dna , hamster , cell culture , galactose , mannose , biology , microbiology and biotechnology , receptor , genetics , gene
Carbon dioxide is a metabolic byproduct of mammalian cell metabolism that can accumulate in poorly ventilated cultures. A buildup of CO 2 at constant pH will be accompanied by an increase in medium osmolality. We have examined the glycosylation of tissue plasminogen activator (tPA) produced under serum‐free conditions by recombinant Chinese hamster ovary (CHO) cells (MT2‐1–8 cell line) in response to elevated pCO 2 at constant or elevated osmolality. The proportion of sialic acids comprising N ‐glycolylneuraminic acid decreased from 2.3–4.0% under 36 mmHg pCO 2 to 1.5–2.2% under 250 mmHg pCO 2 . No changes were observed in the total sialic acid content, the content of other monosaccharides, the relative amounts of type I and type II tPAs, the distribution of surface charges, or the proportion of high‐mannose oligosaccharides—even though these conditions have previously been shown to inhibit the specific growth rate of MT2‐1–8 cells by 30–40% and the specific tPA production rate by as much as 40%. These results suggest robust glycosylation of tPA by CHO cells.