L-Lysine

Absorption

Absorbed from the lumen of the small intestine into the enterocytes by an active transport process

Description

See ι-LYSINE MONOCHLORIDE.

Description

L-Lysine is one of the nine essential amino acids—essential because the human body cannot synthesize them so they must therefore be included in a healthy diet. It is one of the four common α-amino acids to have a nitrogen atom in its side chain.
In 1889, Edmund Drechsel at the University of Freiburg (Germany) isolated lysine by hydrolyzing casein, a protein found in milk. The molecule’s structure was elucidated in 1902 by Emil Fischer and Fritz Weigert at the University of Berlin; they synthesized it and compared it with the natural product.
Fortunately for humans, lysine is abundant in a wide range of high-protein foods, including red meat, some fish, eggs, cheese, and legumes. As with most amino acids, lysine’s key role in the body is the formation of proteins.
Why are we featuring lysine during National Chemistry Week? The theme for this year’s NCW is catalysis—and lysine plays a key role in a biocatalytic–organocatalytic process reported last year by Kelsey N. Stewart, Emily G. Hicks, and Dylan W. Domaille* at the Colorado School of Mines (Golden).
The researchers sought to biosynthesize value-added chemicals from renewable feedstocks by using unmodified (i.e., natural) microorganisms rather than engineered ones. They developed a process in which they combined the bacterium Gluconobacter oxidans1 and lysine as cocatalysts for the single-pot conversion of straight-chain aliphatic alcohols to α,β-unsaturated aldehydes. The reaction takes place in water under mild conditions; it is not necessary to isolate the intermediate products.
The specific role of lysine is to prevent the reaction from diverting to a simple oxidation of the starting alcohol to a carboxylic acid. The authors’ proof-of-concept reaction is the conversion of 1-butanol to 2-ethyl-2-hexenal, a chemical that is currently manufactured on a multimillion t/year scale from nonrenewable fossil-fuel feedstocks with rhodium catalysis at elevated temperature and pressure.
The authors conclude, “our study highlights that merging chemical catalysis with in situ biocatalysis is a powerful strategy to increase the complexity and breadth of products available from bioprocesses.”
1. Also known as Gluconobacter oxydans; found in spoiled (oxidized) fruit and fermented beverages.

Chemical properties

White to pale yellow crystalline powder

Chemical properties

L-Lysine is an essential amino acid (a protein building block) that cannot be produced by the body from other nutri ents. It helps ensure adequate absorption of calcium and the formation of collagen for bone, cartilage and connective tissue. This compound is odorless.

Occurrence

Some natural food sources for l-lysine include lima beans, kidney beans, potatoes, corn, red meat, fish and milk.

The Uses of L-Lysine

L-Lysine is an essential amino acid used in human nutrition. It plays a vital role in calcium absorption, building muscle protein and recovering from surgery or sports injuries. It is used for the treatment of herpes infections and cold sores. Its derivatives lysine acetylsalicylate is utilized to treat pain as well as to detoxify the body after heroin use. It is an important additive to animal feed. Further, it is used in many foods, especially red meats, fish and dairy products.

The Uses of L-Lysine

Essential amino acid for human development. Lysine residues are useful in many cellular processes, due to their ability to accept a wide variety of post-translational modifications.

The Uses of L-Lysine

A moderate serotonin antagonist and essential amino acid.

The Uses of L-Lysine

lysine is a skin-conditioning amino acid.

Background

Lysine (abbreviated as Lys or K) is an α-amino acid with the chemical formula HO2CCH(NH2)(CH2)4NH2. This amino acid is an essential amino acid, which means that humans cannot synthesize it. Its codons are AAA and AAG. Lysine is a base, as are arginine and histidine. The ε-amino group acts as a site for hydrogen binding and a general base in catalysis. Common posttranslational modifications include methylation of the ε-amino group, giving methyl-, dimethyl-, and trimethyllysine. The latter occurs in calmodulin. Other posttranslational modifications include acetylation. Collagen contains hydroxylysine which is derived from lysine by lysyl hydroxylase. O-Glycosylation of lysine residues in the endoplasmic reticulum or Golgi apparatus is used to mark certain proteins for secretion from the cell.

Indications

Supplemental lysine has putative anti-herpes simplex virus activity. There is preliminary research suggesting that it may have some anti-osteoporotic activity.

What are the applications of Application

L-Lysine is a moderate serotonin antagonist and essential amino acid

Definition

ChEBI: An L-alpha-amino acid; the L-isomer of lysine.

Preparation

Produced by fermentation. Also produced by use of continuous ion exchange technology.

Biotechnological Production

C. glutamicum and, to a lesser extent, E. coli are the main organisms used today for industrial L-lysine production. The first L-producing strains based on C. glutamicum were reported in 1961, and those based on E. coli in 1995. The advantages of using E. coli versus C. glutamicum include the achievement of higher growth rates at higher fermentation temperatures. The formation of lysine is highly influenced by two enzymes, aspartate kinase (AK) and homoserine dehydrogenase (HDH). AK converts aspartate into aspartate semialdehyde, and is highly feedback-inhibited by lysine and threonine. HDH converts aspartate semialdehyde into homoserine, which is an intermediate for the biosynthesis of threonine, methionine, and isoleucine. L-Lysine–producing strains therefore often contain a deregulated AK and/or a reduced activity HDH. Despite the improvement of the flux from aspartate towards lysine, the availability of key metabolites from the central metabolic pathways is also essential. Here the formation of oxaloacetate directly from phosphoenol pyruvate or via pyruvate is essential for the carbon yield as some unnecessary cycles are included. For example, inactivation of the enzyme phosphoenol pyruvate carboxykinase, which catalyzes the reverse reaction from oxaloacetate to phosphoenol pyruvate gave an improvement in lysine formation. By overexpression of pyruvate carboxylase, the conversion yield of glucose to lysine could be increased by 50 %. With a synthetic lysine hyperproducing strain, containing 12 defined modifications from the wild type, a carbon yield of 0.55 g/g and a product titer of 120 g/L over 30 h fermentation could be obtained.
Today, however, the main commercial process for L-lysine remains the fermentation of C. glutamicum. This is performed in fed-batch mode in large-scale fermenters of up to 500 m3 volume, with production capacities in excess of 100,000 tonnes. The commercial manufacturing process has been comprehensively described by Pfefferle.

Aroma threshold values

Detection: 500 ppm

Synthesis Reference(s)

Journal of the American Chemical Society, 71, p. 3161, 1949 DOI: 10.1021/ja01177a063

General Description

L-Lysine is a basic amino acid.

Pharmacokinetics

Insures the adequate absorption of calcium; helps form collagen ( which makes up bone cartilage & connective tissues); aids in the production of antibodies, hormones & enzymes. Recent studies have shown that Lysine may be effective against herpes by improving the balance of nutrients that reduce viral growth. A deficiency may result in tiredness, inability to concentrate, irritability, bloodshot eyes, retarded growth, hair loss, anemia & reproductive problems.

Safety Profile

An experimental teratogen. Experimental reproductive effects. When heated to decomposition it emits toxic fumes of NOx.

Veterinary Drugs and Treatments

Lysine may be effective in suppressing FHV-1 infections in cats.

Metabolism

Hepatic

Purification Methods

Crystallise L-lysine from aqueous EtOH. [Greenstein & Winitz The Chemistry of the Amino Acids J. Wiley, Vol 3 pp 2097-2122 1961, Kearley & Ingersoll J Am Chem Soc 73 5783 1951, Beilstein 4 IV 2717.]