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Science behind L-Glutamine

Glutamine Power reduces erectile dysfuncton

L Glutamine Power

L-glutamine is an unstable essential amino acid required in cell culture media formulations. Most commercially available media are formulated with free L-glutamine which is either included in the basal formula or added to liquid formulations at time of use. L-glutamine is unstable at physiological pH in liquid media. It breaks down to ammonium and pyroglutamate at rates that make it a problem in many biomanufacturing applications. Today several proprietary media used in biomanufacturing are supplemented with L-glutamine in dipeptide forms, such as alanyl-l-glutamine and glycyl-l-glutamine. A less well defined source of L-glutamine comes from the use of protein hydrolysates, especially gluten hydrolysates.

The concentration of L-glutamine used in classical media ranges from 0.5 mM in Ames’ Medium to 10 mM in MCDB Media 131. The more typical concentrations in media used for biomanufacturing and tissue engineering application is between 2 and 4 mM. DMEM/Ham’s Nutrient Mixture F-12 (50:50) is often used as a starting formulation for proprietary media used with Chinese Hamster Ovay, CHO, cells. L-glutamine in DMEM/F12 Nutrient Mixture is 2.5 mM. L-glutamine in Serum-Free/Protein Free Hybridoma Medium is 2.7 mM. L-glutamine in DMEM, GMEM, IMDM and H-Y medium is 4 mM. IMDM is often used as a starting formulation for proprietary hybridoma cell culture media. Hybridoma cells grow better in concentrations of L-glutamine that are above the average levels found in media.
Because of its chemical instability and importance for cell growth and function, it is critical that the delivery of L-glutamine be optimized to each unique cell culture process. Hence the effective use of L-glutamine and L-glutamine equivalents in cell culture requires an understanding of its chemistry and multiple delivery forms.

Primary Functions of Glutamine in Cell Culture Systems: 

Glutamine Chemical Structure

Glutamine Chemical Structure

Glutamine supports the growth of cells that have high energy demands and synthesize large amounts of proteins and nucleic acids. It is an alternative energy source for rapidly dividing cells and cells that use glucose inefficiently. Cells require nitrogen atoms to build molecules such as nucleotides, amino acids, amino-sugars and vitamins. Ammonium is an inorganic source of nitrogen that exists primarily as a positively charged cation, NH4+, at physiological pH. Ammonium nitrogen used by cells is initially incorporated into organic nitrogen as an amine of glutamate or an amide of glutamine. These two amino acids provide the primary reservoirs of nitrogen for the synthesis of proteins, nucleic acids and other nitrogenous compounds.
Reactions that fix nitrogen into glutamate and glutamine consume energy equivalents. Glutamate is synthesized from ammonium and alpha ketoglutaric acid, a tricarboxylic acid (TCA) cycle intermediate. Its synthesis requires the oxidation of either NADH or NADPH. Glutamine is formed from ammonium and glutamate and its synthesis consumes ATP. The enzymes involved in glutamate synthesis, glutamate dehydrogenase (EC 1.4.1.4) and glutamate synthase (EC 1.4.1.13) are reversible. The enzyme responsible for glutamine synthesis, glutamine synthetase (EC 6.3.1.2), is highly regulated to limit the production of glutamine to cell requirements. The catabolism of glutamine to glutamate and ammonium is mediated by mitochodrial enzymes called glutaminases (EC 3.5.1.2 ). Ammonium produced in vivo can be metabolized to urea. In vitro, ammonium is not metabolized to urea. Under some in vitro conditions, ammonia accumulates in the extracellular medium as ammonium ion.

L-glutamine is an unstable essential amino acid required in cell culture media formulations. Most commercially available media are formulated with free L-glutamine which is either included in the basal formula or added to liquid formulations at time of use. L-glutamine is unstable at physiological pH in liquid media. It breaks down to ammonium and pyroglutamate at rates that make it a problem in many biomanufacturing applications. Today several proprietary media used in biomanufacturing are supplemented with L-glutamine in dipeptide forms, such as alanyl-l-glutamine and glycyl-l-glutamine. A less well defined source of L-glutamine comes from the use of protein hydrolysates, especially gluten hydrolysates.

The concentration of L-glutamine used in classical media ranges from 0.5 mM in Ames’ Medium to 10 mM in MCDB Media 131. The more typical concentrations in media used for biomanufacturing and tissue engineering application is between 2 and 4 mM. DMEM/Ham’s Nutrient Mixture F-12 (50:50) is often used as a starting formulation for proprietary media used with Chinese Hamster Ovay, CHO, cells. L-glutamine in DMEM/F12 Nutrient Mixture is 2.5 mM. L-glutamine in Serum-Free/Protein Free Hybridoma Medium is 2.7 mM. L-glutamine in DMEM, GMEM, IMDM and H-Y medium is 4 mM. IMDM is often used as a starting formulation for proprietary hybridoma cell culture media. Hybridoma cells grow better in concentrations of L-glutamine that are above the average levels found in media.

Because of its chemical instability and importance for cell growth and function, it is critical that the delivery of L-glutamine be optimized to each unique cell culture process. Hence the effective use of L-glutamine and L-glutamine equivalents in cell culture requires an understanding of its chemistry and multiple delivery forms. For a more complete discussion of L-glutamine as a cell culture additive go to Sigma’s Media Expert.
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Primary Functions of Glutamine in Cell Culture Systems:

Glutamine supports the growth of cells that have high energy demands and synthesize large amounts of proteins and nucleic acids. It is an alternative energy source for rapidly dividing cells and cells that use glucose inefficiently. Cells require nitrogen atoms to build molecules such as nucleotides, amino acids, amino-sugars and vitamins. Ammonium is an inorganic source of nitrogen that exists primarily as a positively charged cation, NH4+, at physiological pH. Ammonium nitrogen used by cells is initially incorporated into organic nitrogen as an amine of glutamate or an amide of glutamine. These two amino acids provide the primary reservoirs of nitrogen for the synthesis of proteins, nucleic acids and other nitrogenous compounds.

Reactions that fix nitrogen into glutamate and glutamine consume energy equivalents. Glutamate is synthesized from ammonium and alpha ketoglutaric acid, a tricarboxylic acid (TCA) cycle intermediate. Its synthesis requires the oxidation of either NADH or NADPH. Glutamine is formed from ammonium and glutamate and its synthesis consumes ATP. The enzymes involved in glutamate synthesis, glutamate dehydrogenase (EC 1.4.1.4) and glutamate synthase (EC 1.4.1.13) are reversible. The enzyme responsible for glutamine synthesis, glutamine synthetase (EC 6.3.1.2), is highly regulated to limit the production of glutamine to cell requirements. The catabolism of glutamine to glutamate and ammonium is mediated by mitochodrial enzymes called glutaminases (EC 3.5.1.2 ). Ammonium produced in vivo can be metabolized to urea. In vitro, ammonium is not metabolized to urea. Under some in vitro conditions, ammonia accumulates in the extracellular medium as ammonium ion.

L-glutamine can also be used to synthesize gamma-amniobutyric acid (GABA) which is a neurotransmitter which sustains proper mental functioning and coordination. It also helps regulate osmotic balance in the body due to its reliance on sodium channels for transport. It also aids in blood pH balance by releasing bicarbonate ions in the kidney to reduce acidity or releasing hydrogen ions in the liver to reduce alkalinity. By removing N in the process of being converted to L-glutamine from glutamic acid, it also removes ammonia from the body and brain which results in clearer thinking and regulates genes involved in biosynthesis of DNA and RNA. It also aids in reparation of connective tissue damage brought about by disease, excessive catabolism of muscles and tissue damage and can help suppress sugar and alcohol cravings as well as treat arthritis and Alzheimer’s when administered supplementally. Because of its use in repairing muscles quickly, it is often used as a protein supplement in weight loss and muscle building to increase anabolism in muscles and help them grow faster.

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