enzymology Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

, a polygalacturonate 4-alpha-galacturonosyltransferase () is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...

that

catalyzes Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

the

chemical reaction A chemical reaction is a process that leads to the IUPAC nomenclature for organic transformations, chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the pos ...

:UDP-D-galacturonate + (1,4-alpha-D-galacturonosyl)n

\rightleftharpoons

UDP + (1,4-alpha-D-galacturonosyl)n⁺1 Thus, the two substrates of this enzyme are UDP-D-galacturonate and (1,4-alpha-D-galacturonosyl)n, whereas its two

products Product may refer to: Business * Product (business), an item that serves as a solution to a specific consumer problem. * Product (project management), a deliverable or set of deliverables that contribute to a business solution Mathematics * Produ ...

are UDP and (1,4-alpha-D-galacturonosyl)n+1. This enzyme belongs to the family of

glycosyltransferase Glycosyltransferases (GTFs, Gtfs) are enzymes ( EC 2.4) that establish natural glycosidic linkages. They catalyze the transfer of saccharide moieties from an activated nucleotide sugar (also known as the "glycosyl donor") to a nucleophilic glycos ...

s, specifically the hexosyltransferases. The

systematic name A systematic name is a name given in a systematic way to one unique group, organism, object or chemical substance, out of a specific population or collection. Systematic names are usually part of a nomenclature. A semisystematic name or semitrivial ...

of this enzyme class is UDP-D-galacturonate:1,4-alpha-poly-D-galacturonate 4-alpha-D-galacturonosyltransferase. Other names in common use include UDP galacturonate-polygalacturonate alpha-galacturonosyltransferase, uridine diphosphogalacturonate-polygalacturonate, and alpha-galacturonosyltransferase. This enzyme participates in

starch and sucrose metabolism Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets, ...

and

nucleotide sugars metabolism In nucleotide sugar metabolism a group of biochemicals known as nucleotide sugars act as donors for sugar residues in the glycosylation reactions that produce polysaccharides. They are substrates for glycosyltransferases. The nucleotide sugars ...

Indications

Polygalacturonate salts can be used clinically to treat the GI reactions that are due to

Quinidine Quinidine is a class IA antiarrhythmic agent used to treat heart rhythm disturbances. It is the enantiomer of antimalarial agent quinine, originally derived from the bark of the cinchona tree. The drug causes increased action potential duratio ...

References

* EC 2.4.1 Enzymes of unknown structure {{2.4-enzyme-stub