In the realm of cellular biology, the nutrient landscape is key to maintaining robust cell cultures. Among these essential nutrients, glutamine is a critical amino acid that fuels numerous cellular processes. Whether you’re a researcher or a science enthusiast, understanding glutamine’s role can provide valuable insights into cellular metabolism and experimental optimization. In this blog post, we will delve into the science behind glutamine, its crucial functions in cell culture, and how to help ensure your cells receive the most stable form of this vital nutrient. Join us as we explore the indispensable role of glutamine in cellular health and research.
1. What is glutamine?
Glutamine is a non-essential amino acid that plays a pivotal role in various metabolic processes. It is the most abundant free amino acid in the human body and is involved in numerous physiological functions beyond protein synthesis. Glutamine acts as a nitrogen donor, which is critical for the synthesis of nucleotides, amino sugars, and other amino acids. It also serves as a carbon source in the citric acid cycle, contributing to cellular energy production. In the brain, glutamine is a precursor for neurotransmitters such as glutamate and GABA, influencing neurological functions.
2. What is the purpose of L-glutamine?
L-glutamine, the L-isomer of glutamine, is biologically active and essential for several cellular functions. It is a key substrate for the synthesis of proteins and nucleotides, supporting cell growth and division. L-glutamine is also crucial for maintaining redox balance within cells by contributing to the synthesis of glutathione, a major antioxidant. In rapidly dividing cells, such as those in the immune system and intestinal epithelium, L-glutamine serves as a primary energy source. As a result, it supports the integrity of the gut mucosa and enhances immune cell function, making it indispensable for overall cellular health and homeostasis.
3. Why is L-glutamine in cell culture media?
In cell culture, L-glutamine is an essential supplement because it provides the necessary nutrients for cell proliferation and maintenance. Cultured cells rely on L-glutamine for the synthesis of proteins, nucleotides, and other critical biomolecules. Its presence in the media ensures that cells have a steady supply of this indispensable amino acid, which supports their energy metabolism and growth. Without sufficient L-glutamine, cells may exhibit reduced viability, slower growth rates, and diminished ability to perform essential functions, compromising the integrity of experimental results.
4. Does L-glutamine degrade in complete media?
Yes, L-glutamine degrades in complete media over time. In aqueous solutions, especially at physiological temperatures (37°C), L-glutamine can spontaneously break down into ammonia and pyrrolidone carboxylic acid (Figure 1). This degradation not only reduces the availability of L-glutamine but also leads to the accumulation of ammonia, which is toxic to cells. High ammonia levels can alter the pH of the culture media, negatively affect cell metabolism, and impair protein glycosylation, leading to suboptimal cell growth and function.
Figure 1. L-glutamine spontaneously decomposes into ammonia and pyrrolidone carboxylic acid at a rate dependent on pH and temperature.
5. How can I get stable L-glutamine for my cells?
To mitigate the instability of L-glutamine in cell culture media, researchers can use stabilized forms of this amino acid. One effective solution is the Gibco™ GlutaMAX™ Supplement, which contains L-alanyl-L-glutamine, a dipeptide form of L-glutamine. This stabilized form resists degradation and significantly reduces the production of ammonia, even during prolonged incubation at 37°C (Figure 2).
Figure 2. A) L-glutamine degrades faster than GlutaMAX Supplement in media at 37°C. DMEM was supplemented with GlutaMAX Supplement or L-glutamine, dispensed into vials, and stored at 37°C. Samples were taken daily and frozen at –20°C. Levels of GlutaMAX Supplement and L-glutamine were determined by HPLC. B) Ammonia levels in supplemented media.DMEM was supplemented with GlutaMAX Supplement or L-glutamine, dispensed into vials, and stored at 37°C. Samples were taken daily and frozen at –20°C. Levels of ammonia were determined by HPLC.
When cells require L-glutamine, they are able to enzymatically break the stable dipeptide into its individual L-glutamine and L-alanine forms and then metabolize them to use in the numerous pathways and functions they support (Figure 3). Utilizing GlutaMAX Supplement can enhance the stability of cell culture media, ensure consistent cell performance, and extend the viability of cultures, thereby optimizing experimental outcomes.
Figure 3. GlutaMAX supplement allows for controlled delivery of L-glutamine from media to cells in culture.
In conclusion, understanding the role and stability of L-glutamine in cell culture is crucial for optimizing cell growth and experimental results. By choosing stabilized alternatives like GlutaMAX Supplement, researchers can help ensure healthier, more productive cell cultures. For more information on how to maximize your cell cultures using media with GlutaMAX Supplement, visitthermofisher.com/glutamax.
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- Find GlutaMAX Media with the Gibco Media Selection Tool
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- Read more about how our media, FBS, and plastics are validated for exceptional product performance so that you can culture with confidence.
Sources:
- Yoo HC, Yu YC, Sung Y, Han JM. Glutamine reliance in cell metabolism. Exp Mol Med. 2020 Sep;52(9):1496-1516. doi: 10.1038/s12276-020-00504-8. Epub 2020 Sep 17. PMID: 32943735; PMCID: PMC8080614.
- Gibco GlutaMAX supplement Brochure