Acylation - substitution in the molecule organic compounds of hydrogen or metal acyl, i.e. the balance of molecules of organic acids. A special case of A. is acetylation - accession balance acetic acid CH3WITH-. Acylation used in the pharmaceutical industry in the synthesis of some drugs. In the body reaction A. proceed with participation of special substances - coenzyme acylation COA (KoA-SH). Acid initially activated by connecting with sulfhydryl group KoA-SH (formed acyl-S-KoA). This reaction proceeds with energy use high energy ties adenosine triphosphate (ATP). The balance of acid then transferred to acyl-S-KoA on Allilueva substance. In this way occurs, for example, accession residues of fatty acids (stearin and others) to glycerophosphoric acid in the synthesis of fats: 1) KoA-SH + stearic acid + ATP → stearyl-S-KoA + ADP + pirofosfata acid; 2) stearyl-S-KoA + glycerine.hola acid → stearylglycyrrhetinate acid + KoA-SH.
Critical in the metabolism is active form acetic acid - acetyl-S-KoA, which is formed by aerobic decomposition of carbohydrates, amino acids, fatty acids. On the other hand, acetyl-S-KoA is involved in the synthesis of various substances, including fatty acids and amino acids. Thus, acetyl-S-KoA is a link, which crossed the path of the exchange of the main components of the body. In addition, the balance of acetic acid acetyl-S-KoA can be oxidized to CO2 and H2O in the tricarboxylic acid cycle (see biological Oxidation), and the energy of this oxidation process is accumulated in the ATP. Two molecules acetyl-S-KoA can interact with the formation of acetoacetyl-S-KoA; the connection breaks down into acetoacetic acid and KoA-SH. Significant also A. role in the processes of neutralization and allocation of toxic or not of the body's own substances. Benzoic acid he is neutralized in the liver by the education hippuric acid. Initially formed benzoyl-S-KoA, which Allium glycine forms hippuric acid. This property liver based functional trial of Quick. Many drugs (sulfonamides, ftivazide, PASK and others) in a large part excreted in the form of acetyl derivatives.
The reactions of biological A. also include the biosynthesis of proteins (see). In this reaction is not involved COA: amino acid is activated by carboxyl group through education anhydrite connection with danilovoy acid. Activated amino acid Allium other amino acids in the amino group, resulting in the formation of the peptide bond. Cm. also the Metabolism and energy.