enzymology An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

, a sarsasapogenin 3β-glucosyltransferase () is an

enzyme An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...

that

catalyzes Catalysis () is the increase in rate of a chemical reaction due to an added substance known as a catalyst (). Catalysts are not consumed by the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recycles quick ...

the

chemical reaction A chemical reaction is a process that leads to the chemistry, chemical transformation of one set of chemical substances to another. When chemical reactions occur, the atoms are rearranged and the reaction is accompanied by an Gibbs free energy, ...

:UDP-glucose + sarsasapogenin UDP + sarsasapogenin 3-''O''-β-D-glucoside Thus, the two substrates of this enzyme are

UDP-glucose Uridine diphosphate glucose (uracil-diphosphate glucose, UDP-glucose) is a nucleotide sugar. It is involved in glycosyltransferase reactions in metabolism. Functions UDP-glucose is used in nucleotide sugar metabolism as an activated form of g ...

and

sarsasapogenin Sarsasapogenin is a steroidal sapogenin, that is the aglycosidic portion of a plant saponin. It is named after sarsaparilla (''Smilax'' sp.),. a family of climbing plants found in subtropical regions. It was one of the first sapogenins to be ident ...

3β,5β,25''S'')-spirostan-3-ol whereas its two

products Product may refer to: Business * Product (business), an item that can be offered to a market to satisfy the desire or need of a customer. * Product (project management), a deliverable or set of deliverables that contribute to a business solution ...

are UDP and sarsasapogenin 3-''O''-β-D-glucoside. The enzyme was first isolated from the root of the common

asparagus Asparagus (''Asparagus officinalis'') is a perennial flowering plant species in the genus ''Asparagus (genus), Asparagus'' native to Eurasia. Widely cultivated as a vegetable crop, its young shoots are used as a spring vegetable. Description ...

(''

Asparagus officinalis Asparagus (''Asparagus officinalis'') is a perennial flowering plant species in the genus ''Asparagus (genus), Asparagus'' native to Eurasia. Widely cultivated as a vegetable crop, its young shoots are used as a spring vegetable. Description ...

''). It is specific for substrate sterols with the uncommon 5β-configuration (sarsasapogenin and smilagenin), that is with a ''cis''-linkage between the A and B rings of the steroid nucleus. 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 gl ...

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 semitrivi ...

of this enzyme class is UDP-glucose:(3β,5β,25''S'')-spirostan-3-ol 3-''O''-β-D-glucosyltransferase. This enzyme is also called uridine diphosphoglucose-sarsasapogenin glucosyltransferase.

References

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