Supplementation with glycine is a common strategy used to improve protein production in mammalian cell culture, particularly in Chinese hamster ovary (CHO) cells. Glycine is a non-essential amino acid that is involved in the synthesis of proteins, nucleotides, and other important biomolecules.
Supplementation with glycine can enhance cell growth, viability, and protein production by several mechanisms. First, glycine can serve as a building block for protein synthesis and help to support the high demand for amino acids during cell proliferation. Second, glycine can act as an osmoprotectant, helping cells to maintain their osmotic balance and prevent cell death during periods of osmotic stress. Third, glycine can act as a scavenger of reactive oxygen species (ROS), which are generated during cell metabolism and can damage cells and proteins.
In CHO cells, glycine supplementation has been shown to improve protein productivity by up to 50% in some cases. The optimal concentration of glycine for CHO cell culture can vary depending on the cell line and culture conditions, but concentrations ranging from 1-10 mM are commonly used.
Glycine supplementation is just one of many strategies used to optimize cell culture conditions for protein production. Other strategies include optimization of media components, cell density, culture duration, and culture pH, among others.