![]() Skeletal formula of L-lysine
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Names | |||
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IUPAC names
L-lysine
D-lysine | |||
Systematic IUPAC name
(2S)-2,6-Diaminohexanoic acid (L-lysine)
(2R)-2,6-Diaminohexanoic acid (D-lysine) | |||
Other names
Lysine, D-lysine, L-lysine, LYS, h-Lys-OH
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Identifiers | |||
3D model (JSmol)
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ChEBI | |||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard | 100.000.673 | ||
KEGG | |||
PubChem CID
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UNII |
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CompTox Dashboard (EPA)
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Properties | |||
C6H14N2O2 | |||
Molar mass | 146.190 g·mol−1 | ||
1.5 kg/L | |||
Pharmacology | |||
B05XB03 (WHO) | |||
Supplementary data page | |||
Lysine (data page) | |||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Lysine (symbol Lys or K)[2] is an α-amino acid that is a precursor to many proteins. It contains an α-amino group (which is in the protonated −NH+3 form when dissolved in water), an α-carboxylic acid group (which is in the deprotonated −COO− form when dissolved in water), and a side chain lysyl ((CH2)4NH2), classifying it as a basic, charged (at physiological pH), aliphatic amino acid. It is encoded by the codons AAA and AAG. Like almost all other amino acids, the α-carbon is chiral and lysine may refer to either enantiomer or a racemic mixture of both. For the purpose of this article, lysine will refer to the biologically active enantiomer L-lysine, where the α-carbon is in the S configuration.
The human body cannot synthesize lysine. It is essential in humans and must therefore be obtained from the diet. In organisms that synthesise lysine, two main biosynthetic pathways exist, the diaminopimelate and α-aminoadipate pathways, which employ distinct enzymes and substrates and are found in diverse organisms. Lysine catabolism occurs through one of several pathways, the most common of which is the saccharopine pathway.
Lysine plays several roles in humans, most importantly proteinogenesis, but also in the crosslinking of collagen polypeptides, uptake of essential mineral nutrients, and in the production of carnitine, which is key in fatty acid metabolism. Lysine is also often involved in histone modifications, and thus, impacts the epigenome. The ε-amino group often participates in hydrogen bonding and as a general base in catalysis. The ε-ammonium group (−NH+3) is attached to the fourth carbon from the α-carbon, which is attached to the carboxyl (−COOH) group.[3]
Due to its importance in several biological processes, a lack of lysine can lead to several disease states including defective connective tissues, impaired fatty acid metabolism, anaemia, and systemic protein-energy deficiency. In contrast, an overabundance of lysine, caused by ineffective catabolism, can cause severe neurological disorders.
Lysine was first isolated by the German biological chemist Ferdinand Heinrich Edmund Drechsel in 1889 from hydrolysis of the protein casein,[4] and thus named it Lysin, from Greek λύσις (lysis) 'loosening'.[5][6] In 1902, the German chemists Emil Fischer and Fritz Weigert determined lysine's chemical structure by synthesizing it.[7]
The one-letter symbol K was assigned to lysine for being alphabetically nearest, with L being assigned to the structurally simpler leucine, and M to methionine.[8]
From p. 256:] " … die darin enthaltene Base hat die Formel C6H14N2O2. Der anfängliche Irrthum ist dadurch veranlasst worden, dass das Chloroplatinat nicht, wie angenommen ward, Krystallwasser, sondern Krystallalkohol enthält, … " ( … the base [that's] contained therein has the [empirical] formula C6H14N2O2. The initial error was caused by the chloroplatinate containing not water in the crystal (as was assumed), but ethanol … )
From p. 469:] " … die Base C6H14N2O2, welche mit dem Namen Lysin bezeichnet werden mag, … " ( … the base C6H14N2O2, which may be designated with the name "lysine", … ) [Note: Ernst Fischer was a graduate student of Drechsel.]