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 leucine dehydrogenase () 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 ...

:L-leucine + H₂O + NAD⁺

\rightleftharpoons

4-methyl-2-oxopentanoate + NH₃ + NADH + H⁺ The 3 substrates of this enzyme are

L-leucine Leucine (symbol Leu or L) is an essential amino acid that is used in the biosynthesis of proteins. Leucine is an α-amino acid, meaning it contains an α-amino group (which is in the protonated −NH3+ form under biological conditions), an α- ca ...

, H₂O, and NAD⁺, whereas its 4 products are 4-methyl-2-oxopentanoate, NH₃, NADH, and H⁺. This enzyme belongs to the family of

oxidoreductase In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule, the reductant, also called the electron donor, to another, the oxidant, also called the electron acceptor. This group of enzymes usually ut ...

s, specifically those acting on the CH-NH2 group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-leucine:NAD+ oxidoreductase (deaminating). Other names in common use include L-leucine dehydrogenase, L-leucine:NAD+ oxidoreductase, deaminating, and LeuDH. This enzyme participates in valine, leucine and isoleucine degradation and

valine, leucine and isoleucine biosynthesis Amino acid synthesis is the set of biochemical processes (metabolic pathways) by which the amino acids are produced. The substrates for these processes are various compounds in the organism's diet or growth media. Not all organisms are able to sy ...

Structural studies

As of late 2007, only one

structure 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 ...

has been solved for this class of enzymes, with the PDB accession code .

References

* * EC 1.4.1 NADH-dependent enzymes Enzymes of known structure {{1.4-enzyme-stub