title: S-Sulfocysteine simplifies fed-batch processes and increases the CHO specific productivity via anti-oxidant activity.
abstract: Industrial fed-batch cultivation of mammalian cells is used for the production of therapeutic proteins such as monoclonal antibodies. Besides medium ensuring initial growth, feeding is necessary to improve growth, viability and antibody production. Established processes include a slight acidic main feed and a separate alkaline feed containing l-tyrosine and l-cysteine. Since l-cysteine is not stable at neutral pH, a new derivative, S-sulfocysteine, was tested in neutral pH feeds. In small scale fed-batch processes, the S-sulfocysteine process yielded a comparable maximum viable cell density, prolonged viability and increased titer compared to the two feed system. Bioreactor experiments confirmed the increase in specific productivity. In depth characterization of the monoclonal antibody indicated no change in the glycosylation, or charge variant pattern whereas peptide mapping experiments were not able to detect any integration of the modified amino acid in the sequence of the monoclonal antibody. Finally, the mechanism of action of S-sulfocysteine was investigated, and results pointed out the anti-oxidative potential of the molecule, mediated through an increase in superoxide dismutase enzyme levels and in the total intracellular glutathione pool. Finally, we propose that the increase in specific productivity obtained in the S-sulfocysteine process results from the anti-oxidative properties of the molecule.
authors.affiliation: Merck KGaA, Merck Life Sciences, Upstream Cell Culture Media R&D, Frankfurter Strasse 250, 64293 Darmstadt, Germany. Electronic address: Caroline.Hecklau@external.merckgroup.com.
authors.forename: Caroline
authors.initials: C
authors.lastname: Hecklau
authors.affiliation: Merck KGaA, Merck Life Sciences, Upstream Cell Culture Media R&D, Frankfurter Strasse 250, 64293 Darmstadt, Germany. Electronic address: Sascha.Pering@external.merckgroup.com.
authors.forename: Sascha
authors.initials: S
authors.lastname: Pering
authors.affiliation: Merck KGaA, Merck Life Sciences, Upstream Cell Culture Media R&D, Frankfurter Strasse 250, 64293 Darmstadt, Germany. Electronic address: Ronja.Seibel@merckgroup.com.
authors.forename: Ronja
authors.initials: R
authors.lastname: Seibel
authors.affiliation: Merck KGaA, Merck Life Sciences, Upstream Cell Culture Media R&D, Frankfurter Strasse 250, 64293 Darmstadt, Germany. Electronic address: Alisa.Schnellbaecher@merckgroup.com.
authors.forename: Alisa
authors.initials: A
authors.lastname: Schnellbaecher
authors.affiliation: Merck KGaA, Merck Life Sciences, Upstream Cell Culture Media R&D, Frankfurter Strasse 250, 64293 Darmstadt, Germany. Electronic address: Maria.Wehsling@merckgroup.com.
authors.forename: Maria
authors.initials: M
authors.lastname: Wehsling
authors.affiliation: Merck KGaA, Central Analytical Services, Frankfurter Strasse 250, 64293 Darmstadt, Germany. Electronic address: Thomas.Eichhorn@merckgroup.com.
authors.forename: Thomas
authors.initials: T
authors.lastname: Eichhorn
authors.affiliation: Merck KGaA, Merck Life Sciences, Upstream Cell Culture Media R&D, Frankfurter Strasse 250, 64293 Darmstadt, Germany. Electronic address: Joerg.von.Hagen@merckgroup.com.
authors.forename: Joerg von
authors.initials: Jv
authors.lastname: Hagen
authors.affiliation: Merck KGaA, Merck Life Sciences, Upstream Cell Culture Media R&D, Frankfurter Strasse 250, 64293 Darmstadt, Germany. Electronic address: Aline.Zimmer@merckgroup.com.
authors.forename: Aline
authors.initials: A
authors.lastname: Zimmer
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D000911:Antibodies, Monoclonal / Q000096:biosynthesis / Q000187:drug effects / Q000378:metabolism; D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology*; D061249:Batch Cell Culture Techniques / Q000379:methods*; D019149:Bioreactors; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D003470:Culture Media; D003545:Cysteine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D005978:Glutathione / Q000378:metabolism; D006031:Glycosylation / Q000187:drug effects; D006863:Hydrogen-Ion Concentration; D010449:Peptide Mapping; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000596:Amino Acids; D000911:Antibodies, Monoclonal; D000975:Antioxidants; D003470:Culture Media; D014443:Tyrosine; C011119:S-sulphocysteine; D005978:Glutathione; D003545:Cysteine
keywords: Cysteine stability; Fed-batch; Monoclonal antibody; Productivity; S-Sulfocysteine; Single feed