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Apparent heterogeneity of recombinant interferon γ receptors produced in prokaryotic and eukaryotic expression systems
Author(s) -
Fountoulakis Michael
Publication year - 1996
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/(sici)1097-4660(199602)65:2<123::aid-jctb400>3.0.co;2-6
Subject(s) - glycosylation , recombinant dna , chinese hamster ovary cell , biology , biochemistry , receptor , escherichia coli , fusion protein , polyacrylamide gel electrophoresis , cleavage (geology) , gel electrophoresis , enzyme , gene , paleontology , fracture (geology)
Recombinant proteins show several types of heterogeneity and post‐translational modifications which are usually related to their production system. The apparent heterogeneity of recombinant interferon γ receptors and interferon γ receptor–immunoglobulin G fusion proteins expressed in Escherichia coli, baculovirus‐infected insect cells and Chinese hamster ovary cells have been studied. In general, all proteins tested showed some type of heterogeneity which was detectable by sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The E. coli ‐derived receptor included non‐native conformations involving mispaired or non‐formed disulfides. This type of heterogeneity affected the biological activity of the protein. In addition, the prokaryotic protein had trapped phosphoric acid during downstream processing. The phosphoric acid entrapment did not affect ligand binding capacity. The eukaryotic proteins showed heterogeneity because of the unequal cleavage of the signal peptide and because of differences in glycosylation. The latter types of heterogeneity did not affect activity. Glycosylation‐related heterogeneity was partially derived from the unequal utilization of the potential N‐glycosylation sites and differently affected the apparent molecular masses and migrations of the proteins on polyacrylamide gels. The results may be useful in characterization studies of recombinant proteins.