Acetyl phosphate is an monophosphate with an

acetyl group In organic chemistry, an acetyl group is a functional group denoted by the chemical formula and the structure . It is sometimes represented by the symbol Ac (not to be confused with the element actinium). In IUPAC nomenclature, an acetyl grou ...

linked to one of its oxygen atoms. It plays a role in '' E.coli'', human, and mouse metabolism. Acetyl phosphate has a molecular formula of .

Discovery

Fritz Albert Lipmann Fritz Albert Lipmann (; June 12, 1899 – July 24, 1986) was a German-American biochemist and a co-discoverer in 1945 of coenzyme A. For this, together with other research on coenzyme A, he was awarded the Nobel Prize in Physiology or Medicine in ...

discovered that

oxidation Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...

pyruvic acid Pyruvic acid (CH3COCOOH) is the simplest of the keto acids, alpha-keto acids, with a carboxylic acid and a ketone functional group. Pyruvate, the conjugate acid, conjugate base, CH3COCOO−, is an metabolic intermediate, intermediate in several m ...

in biological systems was dependent on the presence of inorganic

phosphate Phosphates are the naturally occurring form of the element phosphorus. In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthop ...

. Lipmann added radioactive phosphate and adenylic acid and found that pyruvate oxidation yielded

adenosine triphosphate Adenosine triphosphate (ATP) is a nucleoside triphosphate that provides energy to drive and support many processes in living cell (biology), cells, such as muscle contraction, nerve impulse propagation, and chemical synthesis. Found in all known ...

. He showed that a crude preparation of the product could transfer phosphate to adenylic acid. After several years, he definitively identified the initial product of pyruvic acid oxidation as acetyl phosphate.

AckA-Pta pathway

Acetyl phosphate is the intermediate of the AckA-Pta pathway and acts as a global signal in ''E. coli''. Acetyl phosphate signals through two-component response regulators, it is unclear if it acts as the direct phospho donor or functions through an indirect mechanism. Pta-AckA pathway utilize two key enzymes Pta ( phosphotransacetylase) and AckA ( acetate kinase). The enzymes interconverts the following molecules

acetyl-CoA Acetyl-CoA (acetyl coenzyme A) is a molecule that participates in many biochemical reactions in protein, carbohydrate and lipid metabolism. Its main function is to deliver the acetyl group to the citric acid cycle (Krebs cycle) to be oxidation, o ...

(A central metabolic intermediate), coenzyme A (HS-CoA), acetyl-phosphate (high energy intermediate), ATP, ADP, Pi (inorganic phosphate), and

acetate An acetate is a salt formed by the combination of acetic acid with a base (e.g. alkaline, earthy, metallic, nonmetallic, or radical base). "Acetate" also describes the conjugate base or ion (specifically, the negatively charged ion called ...

. The forward reaction is the acetate activation and is used when cells need to produce acetyl-CoA with acetyl-phosphate being the intermediate to the product. The reverse direction is acetogenesis and is used when cells excrete excess carbon or regenerate ATP. The following reaction occur using either Pta or AckA :acetyl-CoA + Pi → acetyl-phosphate (Pta) :acetyl-phosphate + ADP → acetate + ATP (AckA). Acetyl phosphate is analogous to

acetyl chloride Acetyl chloride () is an acyl chloride derived from acetic acid (). It belongs to the class of organic compounds called acid halides. It is a colorless, corrosive, volatile liquid. Its formula is commonly abbreviated to AcCl. Synthesis On an ...

and

acetic anhydride Acetic anhydride, or ethanoic anhydride, is the chemical compound with the chemical formula, formula . Commonly abbreviated , it is one the simplest organic acid anhydride, anhydrides of a carboxylic acid and is widely used in the production of c ...

. Its lifetime at room temperature in a neutral solution is several hours and it can be kept for weeks without appreciable deterioration at -35°C. It is stable in acidic solution between pH 5 and 6. In bacteria and

archaea Archaea ( ) is a Domain (biology), domain of organisms. Traditionally, Archaea only included its Prokaryote, prokaryotic members, but this has since been found to be paraphyletic, as eukaryotes are known to have evolved from archaea. Even thou ...

, acetyl phosphate is generated with the phosphorylation of acetyl-CoA. Catalyzed by acetyl phosphate synthase, enzyme found on certain microorganism.Then acetyl phosphate phosphorylates ADP to ATP between the thioester and the phosphate metabolism. Acetyl phosphate can phosphorylate some intermediates in nucleotides synthesis (ribose to ribose-5-phosphate, adenosine to AMP and ADP to ATP) like ATP. At more alkaline pH it tends to acetylate the amino groups on

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

s and the hydroxide groups on

ribose Ribose is a simple sugar and carbohydrate with molecular formula C5H10O5 and the linear-form composition H−(C=O)−(CHOH)4−H. The naturally occurring form, , is a component of the ribonucleotides from which RNA is built, and so this comp ...

Applications

Acetyl phosphate is commercially used for industrial applications as a phosphorylating agent to synthesize

antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

antiviral Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Antiviral drugs are a class of antimicrobials ...

drugs and anticancer agents. Because of its ability to modify proteins and

nucleic acid Nucleic acids are large biomolecules that are crucial in all cells and viruses. They are composed of nucleotides, which are the monomer components: a pentose, 5-carbon sugar, a phosphate group and a nitrogenous base. The two main classes of nuclei ...

s it is mostly used for drug development. It is commonly used in biochemistry research because of its ability as an acyl group donor. Acetyl phosphate can be synthesized in water under ambient conditions from thioacetate. The synthesized AcP is then stable over hours making it both stable and reactive. AcP can behave similarly to ATP in that it can phosphorylate biological substrates. Acetyl phosphate is capable of phosphorylation in water. This aligns with the idea that polymeric enzymes or

ribosome Ribosomes () are molecular machine, macromolecular machines, found within all cell (biology), cells, that perform Translation (biology), biological protein synthesis (messenger RNA translation). Ribosomes link amino acids together in the order s ...

s were preceded by monomer catalysis at the

origin of life Abiogenesis is the natural process by which life arises from abiotic component, non-living matter, such as simple organic compounds. The prevailing scientific hypothesis is that the transition from non-living to organism, living entities on ...

Phosphorylating ADP to ATP

ATP is an important energy source for many living organisms. The most plausible and arguable ancestral mechanism for ATP synthesis is through the substrate-level phosphorylation of ADP to ATP by acetyl phosphate (AcP). With Acetyl phosphate being an intermediate and bridging between a

thioester In organic chemistry, thioesters are organosulfur compounds with the molecular structure . They are analogous to carboxylate esters () with the sulfur in the thioester replacing oxygen in the carboxylate ester, as implied by the thio- prefix ...

and a phosphate metabolism being mentioned above and even the topic of linking acetyl CoA to the substrate-level phosphorylation of ADP can potentially find an early relationship to the prebiotic origins of ATP as the universal energy currency. Acetyl Phosphate shows that it can phosphorylate ADP to ATP in aquatic areas with having iron (III) ion present and it can suggest that the substrate-level phosphorylation could potentially take place in aqueous prebiotic conditions. Acetyl Phosphate's phosphorylation process could lead to researching deeper into the reasons why ATP is the universal source across all life from the beginning of time until now. ATP This phosphorylation process is favored in aqueous solution under mild prebiotic conditions and acetyl phosphate could be the key.

References

{{Reflist Phosphates Acetyl compounds