Estrone sulfotransferase (EST) (), also known as estrogen 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 ...

that catalyzes the

transformation Transformation may refer to: Science and mathematics In biology and medicine * Metamorphosis, the biological process of changing physical form after birth or hatching * Malignant transformation, the process of cells becoming cancerous * Tran ...

of an unconjugated

estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal ac ...

estrone Estrone (E1), also spelled oestrone, is a steroid, a weak estrogen, and a minor female sex hormone. It is one of three major endogenous estrogens, the others being estradiol and estriol. Estrone, as well as the other estrogens, are synthesized ...

into a sulfated estrogen like

estrone sulfate Estrone sulfate, also known as E1S, E1SO4 and estrone 3-sulfate, is a natural, endogenous steroid and an estrogen ester and conjugate. In addition to its role as a natural hormone, estrone sulfate is used as a medication, for instance in menop ...

. It is a steroid sulfotransferase and 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 ...

s, to be specific, the

sulfotransferase Sulfotransferases (SULTs) are transferase enzymes that catalyze the transfer of a sulfo group from a donor molecule to an acceptor alcohol or amine. The most common sulfo group donor is 3'-phosphoadenosine-5'-phosphosulfate (PAPS). In the case o ...

s, which transfer sulfur-containing groups. This enzyme participates in

androgen An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This in ...

and

metabolism Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run c ...

and

sulfur metabolism Sulfur is metabolized by all organisms, from bacteria and archaea to plants and animals. Sulfur is reduced or oxidized by organisms in a variety of forms. The element is present in proteins, sulfate esters of polysaccharides, steroids, ph ...

. Steroid sulfatase is an enzyme that catalyzes the reverse reaction, the transfer of a sulfate to an unconjugated estrogen.

Reaction

In enzymology, an EST is an enzyme that catalyzes the following

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 + estrone

\rightleftharpoons

adenosine 3',5'-bisphosphate + estrone 3-sulfate Thus, the two substrates of this enzyme are 3'-phosphoadenylyl sulfate and

, 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 adenosine 3',5'-bisphosphate and estrone 3-sulfate. The enzyme also catalyzes the same reaction for

estradiol Estradiol (E2), also spelled oestradiol, is an estrogen steroid hormone and the major female sex hormone. It is involved in the regulation of the estrous and menstrual female reproductive cycles. Estradiol is responsible for the development o ...

, with

estradiol sulfate Estradiol sulfate (E2S), or 17β-estradiol 3-sulfate, is a natural, endogenous steroid and an estrogen ester. E2S itself is biologically inactive, but it can be converted by steroid sulfatase (also called estrogen sulfatase) into estradiol, whi ...

as the product.

Types

Two enzymes have been identified that together are thought to represent estrone sulfotransferase (EST): * SULT1A1 (catalyzes the reactions

and, to a lesser extent than SULT1E1,

) *

SULT1E1 Estrogen sulfotransferase is an enzyme that in humans is encoded by the ''SULT1E1'' gene. Sulfotransferase enzymes catalyze the sulfate conjugation of many hormones, neurotransmitters, drugs, and xenobiotic compounds. These cytosolic enzymes are ...

(catalyzes the reactions estrone to estrone sulfate and estradiol to estradiol sulfate)

Function

Structure

As of late 2007, 5

structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...

have been solved for this class of enzymes, with PDB accession codes , , , , and .

Names

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 3'-phosphoadenylyl-sulfate:estrone 3-sulfotransferase. Other names in common use include 3'-phosphoadenylyl sulfate-estrone 3-sulfotransferase, estrogen sulfotransferase, estrogen sulphotransferase, oestrogen sulphotransferase, and 3'-phosphoadenylylsulfate:oestrone sulfotransferase.

Reaction

Types

Function

Structure

Names

See also

References

Further reading