N-epsilon-Acetyl-L-lysine also known as Nepsilon-Acetyllysine or N6-Acetyllysine, belongs to the class of organic compounds known as N-acyl-alpha amino acids. N-acyl-alpha amino acids are compounds containing an alpha amino acid which bears an acyl group at one of its nitrogen atoms. N-epsilon-Acetyl-L-lysine can also be classified as an alpha amino acid or a derivatized alpha amino acid. Technically, N-epsilon-Acetyl-L-lysine is a biologically available sidechain, N-capped form of the proteinogenic alpha amino acid L-lysine. Unlike L-lysine, acetylated lysine derivatives such as N-epsilon-Acetyl-L-lysine are zwitterionic compounds. These are molecules that contains an equal number of positively- and negatively-charged functional groups. N-epsilon-Acetyl-L-lysine is found naturally in eukaryotes ranging from yeast to plants to humans.  N-acetyl amino acids can be produced either via direct synthesis of specific N-acetyltransferases or via the proteolytic degradation of N-acetylated proteins (often histones) by specific hydrolases. N-epsilon-Acetyl-L-lysine can be biosynthesized from L-lysine and acetyl-CoA via the enzyme known as Lysine N-acetyltransferase. Post-translational lysine-acetylation is one of two major modifications of lysine residues in various proteins ‚Äì either N-terminal or N-alpha acetylation or N6 (sidechain) acetylation. Side-chain acetylation of specific lysine residues in the N-terminal domains of core histones is a biochemical marker of active genes. Acetylation is now known to play a major role in eukaryotic transcription. Specifically, acetyltransferase enzymes that act on particular lysine side chains of histones and other proteins are intimately involved in transcriptional activation. By modifying chromatin proteins and transcription-related factors, these acetylases are believed to regulate the transcription of many genes. The best-characterized mechanism is acetylation, catalyzed by histone acetyltransferase (HAT) enzymes. HATs function enzymatically by transferring an acetyl group from acetyl-coenzyme A (acetyl-CoA) to the amino group of certain lysine side chains within a histone's basic N-terminal tail region. Within a histone octamer, these regions extend out from the associated globular domains, and in the context of a nucleosome, they are believed to bind the DNA through charge interactions (positively charged histone tails associated with negatively charged DNA) or mediate interactions between nucleosomes. Lysine acetylation, which neutralizes part of a tail region's positive charge, is postulated to weaken histone-DNA or nucleosome-nucleosome interactions and/or signal a conformational change, thereby destabilizing nucleosome structure or arrangement and giving other nuclear factors, such as the transcription complex, more access to a genetic locus. In agreement with this is the fact that acetylated chromatin has long been associated with states of transcriptional activation. Specific recognition of N6-acetyl-L-lysine is a conserved function of all bromodomains found in different proteins, recognized as an emerging intracellular signalling mechanism that plays critical roles in regulating gene transcription, cell-cycle progression, apoptosis, DNA repair, and cytoskeletal organization (PMID: 9169194 , 10827952 , 17340003 , 16247734 , 9478947 , 10839822 ). N-acetylated amino acids, such as N-epsilon-Acetyl-L-lysine can be released by an N-acylpeptide hydrolase from histones going through proteolytic degradation (PMID: 16465618). Many N-acetylamino acids are classified as uremic toxins if present in high abundance in the serum or plasma (PMID: 26317986; PMID: 20613759). Uremic toxins are a diverse group of endogenously produced molecules that, if not properly cleared or eliminated by the kidneys, can cause kidney damage, cardiovascular disease and neurological deficits (PMID: 18287557).