Heterogeneity of Chinese hamster ovary cell-produced recombinant murine interferon-gamma.

摘要: Chinese hamster ovary cells transformed with a hybrid expression plasmid containing both the murine interferon-gamma (MuIFN-gamma) and dihydrofolate reductase-coding sequences were subjected to selection in stepwise increasing concentrations of methotrexate. By this procedure production rate MuIFN-gamma was increased from an initial level approximately 20,000 500,000 antiviral units per milliliter culture supernatant. [35S]Methionine-labeled proteins secreted by these analyzed sodium dodecyl sulfate-polyacrylamide gel electrophoresis or without prior immunoprecipitation polyclonal monoclonal antibodies against splenocyte-derived MuIFN-gamma. Besides two major components Mr 19,000 38,000, multiplicity minor immunoprecipitated. Cells treated tunicamycin, inhibitor N-glycosylation, secrete 14,000 27,000 only 12,000 13,000. When labeled [35S]cysteine, residue that is present at carboxyl terminus mature MuIFN-gamma, no could be detected growth medium tunicamycin-treated cells. The presented results indicate heterogeneity recombinant ovary-produced due least three cumulative modifications peptide: carboxyl-terminal proteolytic processing (the 13,000 components), variations N-glycosylation (components ranging size 26,500), dimerization 50,000).