Acetylation (or in IUPAC nomenclature ethanoylation) describes a reaction that introduces an acetyl functional group into an organic compound. IUPAC Nomenclature is a system of naming Chemical compounds and of describing the science of Chemistry in general In Organic chemistry, acetyl (ethanoyl is a Functional group, the Acyl of Acetic acid, with Chemical formula - C[[Oxygen In Organic chemistry, functional groups are specific groups of Atoms within Molecules that are responsible for the characteristic Chemical reactions An organic compound is any member of a large class of Chemical compounds whose Molecules contain Carbon. Deacetylation is the removal of the acetyl group.
Moreover, it is that process of introducing an acetyl group (resulting in an acetoxy group) into a compound, specifically, the substitution of an acetyl group for an active hydrogen atom. The Acetoxy group, abbreviated AcO or OAc, is a chemical Functional group of the structure CH3-C(=O-O- Hydrogen (ˈhaɪdrədʒən is the Chemical element with Atomic number 1 A reaction involving the replacement of the hydrogen atom of a hydroxyl group with an acetyl group (CH3 CO) yields a specific ester, the acetate. Hydroxyl in Chemistry stands for a molecule consisting of an Oxygen atom and a Hydrogen atom connected by a Covalent bond. Esters are a class of Chemical compounds and Functional groups Esters consist of an inorganic or organic Acid in which at least An acetate, or ethanoate, is either a salt or Ester of Acetic acid. Acetic anhydride is commonly used as an acetylating agent reacting with free hydroxyl groups. Acetic anhydride is the Chemical compound with the formula (CH3CO2O For example, it is used in the synthesis of Aspirin. Aspirin, or acetylsalicylic acid (ASA (əˌsɛtɨlsælɨˌsɪlɨk ˈæsɨd is a Salicylate drug, often used as an Analgesic to relieve
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Acetylation of proteins
In biology, i. e. in living cells, acetylation occurs as a co-translational and post-translational modification of proteins, for example, histones, p53, and tubulins. The cell is the structural and functional unit of all known living Organisms It is the smallest unit of an organism that is classified as living and is often called Posttranslational modification (PTM is the chemical modification of a Protein after its translation. Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl In Biology, histones are the chief Protein components of Chromatin. p53 (also known as protein 53 or tumor protein 53) is a Transcription factor encoded by the TP53 gene A Tubulin is one of several members of a small family of globular Proteins The most common members of the tubulin family are α-tubulin and β-tubulin the proteins that
N-alpha-terminal Acetylation
Acetylation of the N-terminal alpha-amine of proteins is a widespread modification in eukaryotes. 40-50% of yeast proteins, and 80-90% of human proteins are modified in this manner, and the pattern of modification is found to be conserved throughout evolution. The modification is performed by N-alpha-acetyltransferases (NATs), a sub-family of the GNAT superfamily of acetyltransferases, which also include histone acetyl transferases. The GNATs transfer the acetylgroup from acetyl-coenzyme A to the amine group. The NATs have been most extensively studied in yeast. Here three NAT complexes, NatA/B/C, have been found to perform most N-alpha-terminal acetylations. They have sequence specificity for their substrates, and it is believed that they are associated with the ribosome, where they acetylate nascent polypeptides co-translationally.
In humans, only one NAT complex , the human NatA, has been identified and characterized. Subunits of the human NatA complex have been coupled to cancer-related processes such as hypoxia-response and the beta-catenin pathway. It has been found to be over-expressed in papillary thyroid carcinoma and neuroblastoma.
Despite being such a conserved and widespread modification, little is known about the biological role of N-alpha-terminal acetylation. Proteins such as actin and tropomyosin have been found to be dependent of NatB acetylation to form proper actin filaments. This is yet only an example of the potential importance of this modification.
Histone Acetylation and Deacetylation
In histone acetylation and deacetylation, the histones are acetylated and deacetylated on lysine residues in the N-terminal tail as part of gene regulation. In histone acetylation and deacetylation, the Histones are Acetylated and deacetylated on Lysine residues in the N-terminal tail and on the surface of the Lysine (abbreviated as Lys or K) is an α- Amino acid with the Chemical formula HO2CCH(NH2(CH24NH2 Gene modulation redirects here For information on therapeutic regulation of gene expression see Therapeutic gene modulation.
Typically, these reactions are catalyzed by enzymes with "histone acetyltransferase" (HAt) or "histone deacetylase" (HDAc) activity. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Histone deacetylases (HDAC ( EC number 351 are a class of Enzymes that remove Acetyl groups from an ε-N-acetyl Lysine Amino acid Although it should be noted that HATs and HDACs can modify the acetylation status of non-histone proteins as well.
Tubulin Acetylation and Deacetylation
Tubulin Acetylation and Deacetylation system is well worked out in Chlamydomonas. A Tubulin is one of several members of a small family of globular Proteins The most common members of the tubulin family are α-tubulin and β-tubulin the proteins that Chlamydomonas is a genus of Green alga. They are unicellular Flagellates Chlamydomonas is used as a Model organism for Molecular A Tubulin acetyltransferase located in the axoneme acetylates a specific lysine residue in the α-tubulin subunit in assembled microtubule. Chlamydomonas TEM 17jpg|thumb|Micrograph of thin x-section cut through Chlamydomonas axoneme]]Numerous Eukaryotic cells carry whip-like appendages ( Cilia Once disassembled, this acetylation can be removed by another specific deacetylase which is cytosolic. Thus the axonemal microtubules (long half life) carry this signature acetylation absent from cytosolic microtubules (short half life).
See also
The Acetoxy group, abbreviated AcO or OAc, is a chemical Functional group of the structure CH3-C(=O-O- In Chemistry, acylation (rarely but more formally alkanoylation) is the process of adding an Acyl group to a compound Organic synthesis is a special branch of Chemical synthesis and is concerned with the construction of Organic compounds via Organic reactions OrganicDictionary
acetylation
-noun
- (chemistry) The reaction of a substance with acetic acid or one of its derivatives; the introduction of one or more acetyl groups into a substance
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