Phosphoribosyl pyrophosphate (PRPP) is a pentose phosphate. It is a biochemical intermediate in the formation of

purine Purine is a heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted puri ...

nucleotides Nucleotides are Organic compound, organic molecules composed of a nitrogenous base, a pentose sugar and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both o ...

via inosine-5-monophosphate, as well as in

pyrimidine Pyrimidine (; ) is an aromatic, heterocyclic, organic compound similar to pyridine (). One of the three diazines (six-membered heterocyclics with two nitrogen atoms in the ring), it has nitrogen atoms at positions 1 and 3 in the ring. The oth ...

nucleotide formation. Hence it is a building block for

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

and

RNA Ribonucleic acid (RNA) is a polymeric molecule that is essential for most biological functions, either by performing the function itself (non-coding RNA) or by forming a template for the production of proteins (messenger RNA). RNA and deoxyrib ...

. The vitamins

thiamine Thiamine, also known as thiamin and vitamin B1, is a vitamin – an Nutrient#Micronutrients, essential micronutrient for humans and animals. It is found in food and commercially synthesized to be a dietary supplement or medication. Phosp ...

and

cobalamin Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. One of eight B vitamins, it serves as a vital cofactor (biochemistry), cofactor in DNA synthesis and both fatty acid metabolism, fatty acid and amino a ...

, and the amino acid

tryptophan Tryptophan (symbol Trp or W) is an α-amino acid that is used in the biosynthesis of proteins. Tryptophan contains an α-amino group, an α-carboxylic acid group, and a side chain indole, making it a polar molecule with a non-polar aromat ...

also contain fragments derived from PRPP. It is formed from ribose 5-phosphate (R5P) by the enzyme ribose-phosphate diphosphokinase: : R5pactivation

It plays a role in transferring phospho-ribose groups in several reactions, some of which are salvage pathways: In '' de novo'' generation of purines, the enzyme amidophosphoribosyltransferase acts upon PRPP to create phosphoribosylamine. The

histidine Histidine (symbol His or H) is an essential amino acid that is used in the biosynthesis of proteins. It contains an Amine, α-amino group (which is in the protonated –NH3+ form under Physiological condition, biological conditions), a carboxylic ...

biosynthesis pathway involves the reaction between PRPP and ATP, which activates the latter to ring cleavage. Carbon atoms from ribose in PRPP form the linear chain and part of the imidazole ring in histidine. The same is true for the biosynthesis of tryptophan, with the first step being N-alkylation of

anthranilic acid Anthranilic acid is an aromatic acid with the formula C6H4(NH2)(CO2H) and has a sweetish taste. The molecule consists of a benzene ring, ''ortho''-substituted with a carboxylic acid and an amine. As a result of containing both acidic and basic f ...

catalysed by the enzyme anthranilate phosphoribosyltransferase.

Increased PRPP

Increased levels of PRPP are characterized by the overproduction and accumulation of

uric acid Uric acid is a heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the Chemical formula, formula C5H4N4O3. It forms ions and salts known as urates and acid urates, such as ammonium acid urate. Uric acid is a product of the meta ...

leading to

hyperuricemia Hyperuricaemia or hyperuricemia is an abnormally high level of uric acid in the blood. In the pH conditions of body fluid, uric acid exists largely as urate, the ion form. Serum uric acid concentrations greater than 6 mg/dL for females, 7 ...

and

hyperuricosuria Hyperuricosuria is a medical term referring to the presence of excessive amounts of uric acid in the urine. For men this is at a rate greater than 800 mg/day, and for women, 750 mg/day. Notable direct causes of hyperuricosuria are disso ...

. It is one of the causes of

gout Gout ( ) is a form of inflammatory arthritis characterized by recurrent attacks of pain in a red, tender, hot, and Joint effusion, swollen joint, caused by the deposition of needle-like crystals of uric acid known as monosodium urate crysta ...

. Increased levels of PRPP are present in Lesch–Nyhan Syndrome. Decreased levels of hypoxanthine guanine phosphoribosyl transferase (HGPRT) causes this accumulation, as PRPP is a substrate used by HGPRT during

salvage.

References

{{DEFAULTSORT:Phosphoribosyl Pyrophosphate Organophosphates Monosaccharides

Increased PRPP

See also

References