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 polypeptide N-acetylgalactosaminyltransferase () 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-N-acetyl-D-galactosamine + polypeptide

\rightleftharpoons

UDP + N-acetyl-D-galactosaminyl-polypeptide Thus, the two substrates of this enzyme are UDP-N-acetyl-D-galactosamine and

polypeptide Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A p ...

, 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 N-acetyl-D-galactosaminyl-polypeptide. 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. This enzyme participates in o-glycan biosynthesis and

glycan structures - biosynthesis 1 The terms glycans and polysaccharides are defined by IUPAC as synonyms meaning "compounds consisting of a large number of monosaccharides linked glycosidically". However, in practice the term glycan may also be used to refer to the carbohydrate p ...

. It has 2

cofactors Cofactor may also refer to: * Cofactor (biochemistry), a substance that needs to be present in addition to an enzyme for a certain reaction to be catalysed * A domain parameter in elliptic curve cryptography, defined as the ratio between the order ...

manganese Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy use ...

, and

calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to ...

Nomenclature

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-N-acetyl-D-galactosamine:polypeptide N-acetylgalactosaminyl-transferase. Other names in common use include: * protein-UDP acetylgalactosaminyltransferase, * UDP-GalNAc:polypeptide N-acetylgalactosaminyl transferase, * UDP-N-acetylgalactosamine:kappa-casein polypeptide, * N-acetylgalactosaminyltransferase, * uridine diphosphoacetylgalactosamine-glycoprotein, * acetylgalactosaminyltransferase, * glycoprotein acetylgalactosaminyltransferase, * polypeptide-N-acetylgalactosamine transferase, * UDP-acetylgalactosamine-glycoprotein, * acetylgalactosaminyltransferase, * UDP-acetylgalactosamine:peptide-N-galactosaminyltransferase, * UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase, * UDP-N-acetyl-alpha-D-galactosamine:polypeptide, * N-acetylgalactosaminyltransferase, * UDP-N-acetylgalactosamine-glycoprotein, * N-acetylgalactosaminyltransferase, * UDP-N-acetylgalactosamine-protein N-acetylgalactosaminyltransferase, * UDP-N-acetylgalactosamine:polypeptide, * N-acetylgalactosaminyltransferase, and * UDP-N-acetylgalactosamine:protein N-acetylgalactosaminyl transferase.

References

* * EC 2.4.1 Manganese enzymes Calcium enzymes Enzymes of known structure {{2.4-enzyme-stub