Description
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.
Synonyms
2,6-Diaminohexanoic acid
IUPAC Name
(2S)-2,6-Diaminohexanoic acid
Molecular Formula
C6H14N2O2
Canonical SMILES
C(CCN)CC(C(=O)O)N
InChI
InChI=1S/C6H14N2O2/c7-4-2-1-3-5(8)6(9)10/h5H,1-4,7-8H2,(H,9,10)/t5-/m0/s1
InChI Key
KDXKERNSBIXSRK-YFKPBYRVSA-N
Melting Point
215 °C(lit.)
Solubility
Insoluble in ethanol, ethyl ether, acetone, benzene
Storage
Keep in dark place, inert atmosphere, room temperature
Isomeric SMILES
C(CCN)C[C@@H](C(=O)O)N
Monoisotopic Mass
146.105527694
Refractive Index
26 ° (C=2, 5mol/L HCl)
Stability
Stable. Incompatible with strong oxidizing agents.
Storage Conditions
Store at RT.
Topological Polar Surface Area
89.3 Ų