Keto leucine and keto isoleucine are bioavailable precursors of their respective amino acids in cell culture media.

Highly concentrated cell culture media formulations are essential to develop next generation bioprocesses used to produce therapeutic monoclonal antibodies, fusion proteins, bispecific molecules and mAb fragments. Although cysteine/cystine and tyrosine are the first components preventing the development of highly concentrated complex cell culture media, leucine and isoleucine were identified as the next critical amino acids due to their limited solubility. This work sought to investigate highly soluble and readily bioavailable derivatives of both amino acids that may be used in batch, fed-batch or perfusion processes.

Impact of S-sulfocysteine on fragments and trisulfide bond linkages in monoclonal antibodies.

The quality of recombinant proteins such as monoclonal antibodies produced using Chinese hamster ovary cell-based mammalian systems is dependent on many factors, including cell line, process and cell culture media. Due to these factors, the generated product is heterogeneous and may have chemically-induced modifications or post-translational modifications that affect antibody stability, functionality and, in some cases, patient safety. This study demonstrates that S-sulfocysteine, a cysteine derivative, can increase the antibody specific productivity in different cell lines cultivated with different processes while minimizing trisulfide linkages in generated mAbs, mainly between heavy and light chain.

S-Sulfocysteine simplifies fed-batch processes and increases the CHO specific productivity via anti-oxidant activity.

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.