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 flavonol 3-sulfotransferase () 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 ...

:3'-phosphoadenylyl sulfate + flavonol

\rightleftharpoons

adenosine 3',5'-bisphosphate + flavonol 3-sulfate Thus, the two substrates of this enzyme are 3'-phosphoadenylyl sulfate and a flavonol, whereas its two products are

adenosine 3',5'-bisphosphate Adenosine 3',5'-bisphosphate is a form of an adenosine nucleotide with two phosphate groups attached to different carbons in the ribose ring. This is distinct from adenosine diphosphate, where the two phosphate groups are attached in a chain to th ...

and flavonol 3-sulfate. A specific examples of a flavonol that can act as a substrate is quercetin. This enzyme belongs to the family of

transferase A transferase is any one of a class of enzymes that catalyse the transfer of specific functional groups (e.g. a methyl or glycosyl group) from one molecule (called the donor) to another (called the acceptor). They are involved in hundreds of di ...

s termed the sulfotransferases, which transfer sulfate groups. The systematic name of this enzyme class is 3'-phosphoadenylyl-sulfate:flavonol 3-sulfotransferase.

References

EC 2.8.2 Enzymes of unknown structure {{2.8-enzyme-stub