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A 6-acetamido-3-aminohexanoic acid in which the chiral centre at position 3 has S-configuration." []

A member of the class of beta-amino acids that is the N(6)-acetyl derivative of 3,6-diaminohexanoic acid." []

Glycylleucine is a dipeptide composed of glycine and leucine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. It appears to be a common substrate for glycyl-leucine dipeptidase.

N-alpha-Acetyl-L-lysine also known as Nalpha-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 its terminal nitrogen atom. N-alpha-Acetyl-L-lysine can also be classified as an alpha amino acid or a derivatized alpha amino acid. Technically, N-alpha-Acetyl-L-lysine is a biologically available N-terminal capped form of the proteinogenic alpha amino acid L-lysine. Unlike L-lysine, acetylated lysine derivatives such as N-alpha-Acetyl-L-lysine are zwitterionic compounds. These are molecules that contains an equal number of positively- and negatively-charged functional groups. N-alpha-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 by specific hydrolases. N-terminal acetylation of proteins is a widespread and highly conserved process in eukaryotes that is involved in protection and stability of proteins (PMID: 16465618). About 85% of all human proteins and 68% of all yeast proteins are acetylated at their N-terminus (PMID: 21750686). Several proteins from prokaryotes and archaea are also modified by N-terminal acetylation. The majority of eukaryotic N-terminal-acetylation reactions occur through N-acetyltransferase enzymes or NAT’s (PMID: 30054468). These enzymes consist of three main oligomeric complexes NatA, NatB, and NatC, which are composed of at least a unique catalytic subunit and one unique ribosomal anchor. The substrate specificities of different NAT enzymes are mainly determined by the identities of the first two N-terminal residues of the target protein. The human NatA complex co-translationally acetylates N-termini that bear a small amino acid (A, S, T, C, and occasionally V and G) (PMID: 30054468). NatA also exists in a monomeric state and can post-translationally acetylate acidic N-termini residues (D-, E-). NatB and NatC acetylate N-terminal methionine with further specificity determined by the identity of the second amino acid. N-acetylated amino acids, such as N-alpha-Acetyl-L-lysine can be released by an N-acylpeptide hydrolase from peptides generated by proteolytic degradation (PMID: 16465618). In addition to the NAT enzymes and protein-based acetylation, N-acetylation of free lysine can also occur. In particular, N-alpha-Acetyl-L-lysine can be biosynthesized from L-lysine and acetyl-CoA via the enzyme known as Lysine N-acetyltransferase. Individuals with hyperlysinaemia due to L-lysine alpha-ketoglutarate reductase deficiency will excrete high levels of N-alpha-Acetyl-L-lysine in their urine (PMID: 116084). L-lysine alpha-ketoglutarate reductase deficiency, if untreated, can lead to neurological and behavioral deficits (PMID: 116084). 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).

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 – 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).

Alanylvaline is a dipeptide composed of alanine and valine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.

Glycyl-Isoleucine is a dipeptide composed of glycine and isoleucine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. This dipeptide has not yet been identified in human tissues or biofluids and so it is classified as an 'Expected' metabolite.

Isoleucyl-Glycine is a dipeptide composed of isoleucine and glycine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. This dipeptide has not yet been identified in human tissues or biofluids and so it is classified as an 'Expected' metabolite.

Leucyl-Glycine is a dipeptide composed of leucine and glycine. It is an incomplete breakdown product of protein digestion or protein catabolism. Some dipeptides are known to have physiological or cell-signaling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis. This dipeptide has not yet been identified in human tissues or biofluids and so it is classified as an 'Expected' metabolite.

Valylalanine is a dipeptide composed of valine and alanine. It is an incomplete breakdown product of protein digestion or protein catabolism. Dipeptides are organic compounds containing a sequence of exactly two alpha-amino acids joined by a peptide bond. Some dipeptides are known to have physiological or cell-signalling effects although most are simply short-lived intermediates on their way to specific amino acid degradation pathways following further proteolysis.

A dipeptide formed from D-leucine and glycine residues." []

A N(5)-alkylglutamine where the alkyl group is isopropyl." []

6-Acetamido-2-aminohexanoic acid is an alpha-amino acid. 6-Acetamido-2-azaniumylhexanoate is a natural product found in Phaseolus vulgaris with data available.

A nitrosamine that has butyl and 4-carboxybutyl substituents. It is the principal metabolite of the bladder carcinogen N-butyl-N-(4-hydroxybutyl)nitrosamine (BHBN-4)." []