Lysine

Lysine

Names
IUPAC name Lysine
Other names 2,6-Diaminohexanoic acid; 2,6-Diammoniohexanoic acid
Identifiers
CAS Number	70-54-2 DL N 56-87-1 L Y 923-27-3 D Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:25094 Y
ChEMBL	ChEMBL28328 Y
ChemSpider	843 Y 5747 L Y
ECHA InfoCard	100.000.673
IUPHAR/BPS	724
KEGG	C16440 N
PubChem	866
UNII	K3Z4F929H6 Y
InChI InChI=1S/C6H14N2O2/c7-4-2-1-3-5(8)6(9)10/h5H,1-4,7-8H2,(H,9,10) Y Key: KDXKERNSBIXSRK-UHFFFAOYSA-N Y InChI=1/C6H14N2O2/c7-4-2-1-3-5(8)6(9)10/h5H,1-4,7-8H2,(H,9,10) Key: KDXKERNSBIXSRK-UHFFFAOYAY
SMILES C(CCN)CC(C(=O)O)N
Properties
Chemical formula	C6H14N2O2
Molar mass	146.19 g·mol−1
Solubility in water	1.5kg/L @ 25 °C
Pharmacology
ATC code	B05XB03 (WHO)
Supplementary data page
Structure and properties	Refractive index (n), Dielectric constant (εr), etc.
Thermodynamic data	Phase behaviour solid–liquid–gas
Spectral data	UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N  (what is YN ?)
Infobox references

Lysine (abbreviated as Lys or K), encoded by the codons AAA and AAG, is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH₃⁺ form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO⁻ form under biological conditions), and a side chain lysyl ((CH₂)₄NH₂), classifying it as a charged (at physiological pH), aliphatic amino acid. It is essential in humans, meaning the body cannot synthesize it and thus it must be obtained from the diet.

Lysine is a base, as are arginine and histidine. The ε-amino group often participates in hydrogen bonding and as a general base in catalysis. The ε-amino group (NH₃⁺) is attached to the fifth carbon from the α-carbon, which is attached to the carboxyl (C=OOH) group.

Common posttranslational modifications include methylation of the ε-amino group, giving methyl-, dimethyl-, and trimethyllysine (the latter occurring in calmodulin); also acetylation, sumoylation, ubiquitination, and hydroxylation - producing the hydroxylysine in collagen and other proteins. O-Glycosylation of hydroxylysine residues in the endoplasmic reticulum or Golgi apparatus is used to mark certain proteins for secretion from the cell. In opsins like rhodopsin and the visual opsins (encoded by the genes OPN1SW, OPN1MW, and OPN1LW), retinaldehyde forms a Schiff base with a conserved lysine residue, and interaction of light with the retinylidene group causes signal transduction in color vision (See visual cycle for details). Deficiencies may cause blindness, as well as many other problems due to its ubiquitous presence in proteins.