Record Information
Version1.0
StatusDetected and Quantified
Creation Date2020-12-10 18:52:33 UTC
Update Date2024-04-30 19:33:30 UTC
Metabolite IDMMDBc0000678
Metabolite Identification
Common NameN-Acetylisoleucine
DescriptionN-Acetyl-L-isoleucine or N-Acetylisoleucine, 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-Acetylisoleucine can also be classified as an alpha amino acid or a derivatized alpha amino acid. Technically, N-Acetylisoleucine is a biologically available N-terminal capped form of the proteinogenic alpha amino acid L-isolecuine. 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-acetylisoleucine 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 isoleucine can also occur. In particular, N-Acetylisoleucine can be biosynthesized from L-isoleucine and acetyl-CoA by the enzyme leucine/isoleucine N-acetyltransferase (EC 2.3.1.66). Excessive amounts N-acetyl amino acids including N-acetylisoleucine (as well as N-acetylglycine, N-acetylserine, N-acetylglutamine, N-acetylglutamate, N-acetylalanine, N-acetylmethionine and smaller amounts of N-acetylthreonine, N-acetylleucine, and N-acetylvaline) can be detected in the urine with individuals with acylase I deficiency, a genetic disorder (PMID: 16465618 ). Aminoacylase I is a soluble homodimeric zinc binding enzyme that catalyzes the formation of free aliphatic amino acids from N-acetylated precursors. In humans, Aminoacylase I is encoded by the aminoacylase 1 gene (ACY1) on chromosome 3p21 that consists of 15 exons (OMIM 609924 ). Individuals with aminoacylase I deficiency will experience convulsions, hearing loss and difficulty feeding (PMID: 16465618 ). ACY1 can also catalyze the reverse reaction, the synthesis of acetylated amino acids. Many N-acetylamino acids, including N-acetylisoleucine 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 ).
Structure
Synonyms
ValueSource
N-Acetyl-L-isoleucineHMDB
N-AcetylisoleucineHMDB
Molecular FormulaC8H15NO3
Average Mass173.212
Monoisotopic Mass173.105193347
IUPAC Name(2S,3S)-2-acetamido-3-methylpentanoic acid
Traditional Name(2S,3S)-2-acetamido-3-methylpentanoic acid
CAS Registry NumberNot Available
SMILES
CC[C@H](C)[C@H](NC(C)=O)C(O)=O
InChI Identifier
InChI=1S/C8H15NO3/c1-4-5(2)7(8(11)12)9-6(3)10/h5,7H,4H2,1-3H3,(H,9,10)(H,11,12)/t5-,7-/m0/s1
InChI KeyJDTWZSUNGHMMJM-FSPLSTOPSA-N