In enzymology, a thiamine-diphosphate kinase is an enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 involved in thiamine metabolism. It catalyzes

Catalysis

Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....

 the chemical reaction

Chemical reaction

A chemical reaction is a process that leads to the transformation of one set of chemical substances to another. Chemical reactions can be either spontaneous, requiring no input of energy, or non-spontaneous, typically following the input of some type of energy, such as heat, light or electricity...

thiamine diphosphate + ATP thiamine triphosphate + ADP

Thus, the two substrates

Substrate (biochemistry)

In biochemistry, a substrate is a molecule upon which an enzyme acts. Enzymes catalyze chemical reactions involving the substrate. In the case of a single substrate, the substrate binds with the enzyme active site, and an enzyme-substrate complex is formed. The substrate is transformed into one or...

 of this enzyme are ATP

Adenosine triphosphate

Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...

 and thiamine diphosphate, whereas its two products

Product (chemistry)

Product are formed during chemical reactions as reagents are consumed. Products have lower energy than the reagents and are produced during the reaction according to the second law of thermodynamics. The released energy comes from changes in chemical bonds between atoms in reagent molecules and...

 are ADP

Adenosine diphosphate

Adenosine diphosphate, abbreviated ADP, is a nucleoside diphosphate. It is an ester of pyrophosphoric acid with the nucleoside adenosine. ADP consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase adenine....

 and thiamine triphosphate

Thiamine triphosphate

Thiamine triphosphate is found in most organisms, bacteria, fungi, plants and animals.-Function:It has been proposed that ThTP has a specific role in nerve excitability but this has never been confirmed and recent results suggest that ThTP probably plays a role in cell energy metabolism...

.

This enzyme belongs to the family of transferase

Transferase

In biochemistry, a transferase is an enzyme that catalyzes the transfer of a functional group from one molecule to another . For example, an enzyme that catalyzed this reaction would be a transferase:In this example, A would be the donor, and B would be the acceptor...

s, specifically those transferring phosphorus-containing groups (phosphotransferase

Phosphotransferase

Phosphotransferases are a category of enzymes that catalyze phosphorylation reactions. The general form of the reactions they catalyze is: A—P + B ⇔ B—P + A...

s) with a phosphate group as acceptor. The systematic name of this enzyme class is ATP:thiamine-diphosphate phosphotransferase. Other names in common use include ATP:thiamin-diphosphate phosphotransferase, TDP kinase, thiamin diphosphate kinase, thiamin diphosphate phosphotransferase, thiamin pyrophosphate kinase, thiamine diphosphate kinase, and protein bound thiamin diphosphate:ATP phosphoryltransferase.