Search results
Results from the WOW.Com Content Network
Pyruvate dehydrogenase is an enzyme that catalyzes the reaction of pyruvate and a lipoamide to give the acetylated dihydrolipoamide and carbon dioxide. The conversion requires the coenzyme thiamine pyrophosphate. Pyruvate dehydrogenase is usually encountered as a component, referred to as E1, of the pyruvate dehydrogenase complex (PDC). PDC ...
Pyruvate dehydrogenase complex. Pyruvate dehydrogenase complex (PDC) is a complex of three enzymes that converts pyruvate into acetyl-CoA by a process called pyruvate decarboxylation. [1] Acetyl-CoA may then be used in the citric acid cycle to carry out cellular respiration, and this complex links the glycolysis metabolic pathway to the citric ...
Pyruvate decarboxylation requires a few cofactors in addition to the enzymes that make up the complex. The first is thiamine pyrophosphate (TPP), which is used by pyruvate dehydrogenase to oxidize pyruvate and to form a hydroxyethyl-TPP intermediate. This intermediate is taken up by dihydrolipoyl transacetylase and reacted with a second ...
Crystal Structures allowed for a model in which the enzyme undergoes a 2-A shuttle-like motion of its heterodimers to perform the catalysis. [10] Specifically, the catalytic residue has been identified on the PDHB subunit, the 89th residue, which is a glutamate. [ 11 ]
Pyruvate decarboxylase occurs as a dimer of dimers with two active sites shared between the monomers of each dimer. The enzyme contains a beta-alpha-beta structure, yielding parallel beta-sheets. It contains 563 residue subunits in each dimer; the enzyme has strong intermonomer attractions, but the dimers loosely interact to form a loose ...
Pyruvate oxidation is the step that connects glycolysis and the Krebs cycle. [4] In glycolysis, a single glucose molecule (6 carbons) is split into 2 pyruvates (3 carbons each). Because of this, the link reaction occurs twice for each glucose molecule to produce a total of 2 acetyl-CoA molecules, which can then enter the Krebs cycle.
Malate is oxidized to pyruvate and CO 2, and NADP + is reduced to NADPH. This enzyme belongs to the family of oxidoreductases, to be specific those acting on the CH-OH group of donor with NAD + or NADP + as acceptor. The systematic name of this enzyme class is (S)-malate:NADP + oxidoreductase (oxaloacetate-decarboxylating).
The complex acts to convert pyruvate (a product of glycolysis in the cytosol) to acetyl-coA, which is then oxidized in the mitochondria to produce energy, in the citric acid cycle. By downregulating the activity of this complex, PDK will decrease the oxidation of pyruvate in mitochondria and increase the conversion of pyruvate to lactate in the ...