Metabolism of peptide amino acids by Chinese hamster ovary cells grown in a complex medium

Abstract

Metabolic flux analysis is a useful tool for unraveling relationships between metabolism and cell function. Material balancing can be used to provide estimates of major metabolic pathway fluxes, provided all significant metabolite uptake and production rates are measured. Potential sources of metabolizable material in many serum‐free media formulations are low molecular weight digests of biological material such as yeast extracts and plant or animal tissue hydrolysates. These digests typically contain large amounts of peptides, which may be utilized as amino acids. This article demonstrates the need for accounting for amino acids liberated from peptides in order to accurately estimate pathway fluxes in Chinese hamster ovary cells grown in a complex (hydrolysate containing) medium. A simplified model of central carbon metabolism provides the framework for analyzing external metabolite measurements. Redundant measurements are included to ensure the consistency of data and assumed biochemistry by comparing redundant measurements with their predicted values from a minimum data set, and by expressing the degree of agreement using a statistical “consistency index.” The consistency index tests whether redundancies are satisfied within expected experimental error. For chemostat steady states of CHO cultures grown in a hydrolysate‐supplemented medium, consistent data were obtained only when amino acids liberated from peptides were taken into account. © 1999 John Wiley & Sons, Inc. Biotechnol Bioeng 62: 324–335, 1999.

Combination of yeast hydrolysates to improve CHO cell growth and IgG production

“…On one hand, some results suggested the presence of growth factor-like and anti-apoptotic peptides from plant peptones (Burteau et al 2003;Farges et al 2008;Franek and Katinger 2002) or YE (Sung et al 2004), but without experimental validations. On the other hand, other studies concluded on nutritional efficiency of plant peptones as amino acid sources (Heidemann et al 2000;Nyberg et al 1999). Nevertheless, the addition of nutritional as well as ''bioactive'' compounds may improve the efficiency of energetic cell metabolism.…”

Responses of CHO-DHFR cells to ratio of asparagine to glutamine in feed media: cell growth, antibody production, metabolic waste, glutamate, and energy metabolism

“…To better control cell metabolism and avoid using of animal-derived raw materials and ill-defined hydrolysates, much progress has been made in understanding cell nutrient requirements and development of chemically defined medium including feed formulations over the last 10 years (Wurm 2004;Franek et al 2000;Huang et al 2010;Young 2013). More recently, metabolic flux analysis (MFA) has become a useful tool in medium development for hybridoma Europa et al 2000;Gambhir et al 2003) and CHO cell cultures (Nyberg et al 1999;Altamirano et al 2006), which can help quantifying nutrient demands and metabolite production in cell culture (Zhao et al 2009). …”

Characterization of yeastolate fractions that promote insect cell growth and recombinant protein production

“…The result indicates that glucose, glutamine and vitamins were not limiting factors although glucose and glutamine were depleted in cultures. While the insignificant effect of glutamine supplementation may suggest that Sf-9 cells were able to utilize other components as sources of amino acids, since it is known that cultured animal cells can metabolize dipeptides such as glycyl-L-glutamine (Minamoto et al 1991) and peptides (Nyberg et al 1999). No positive effect of vitamin supplementation may suggest that the vitamins provided by F1 and IPL-41 medium were still sufficient.…”