pyruvate dehydrogenase Flashcards
Pyruvate Dehdrogenase complex subunits
Pyruvate Dehydrogenase
What are the five cofactors of pyruvate dehydrogenase?
TPP, lipoid acid/lipoamide, coenzyme A, FAD, NAD
Where is lipoamide located?
covalently bound to E2 via lysine
Where is TPP located?
tightly bound to EI
Where is coenzymeA located?
disposable substrate fo E2
Where is FAD+ located?
tightly bound to E3
Where is NAD+ located?
disposable substrate fo E3
What are the three enzymes of pdh complex?
pyruvate dehydrogenase, dihydrolipoamide transacetylase, dihydrolipoamide dehydrogenase
Where does the PDH complex take place?
Mitochondrial matrix
What regulated the PDH complex?
allosterically by NADH and acetyl-coA, phosphorylated by E1 phosphorylation and dephospho rylation
What is substrate channeling?
tethering of active sites increase effectiveness
What is the net outcome of the reaction?
acetyl group is stored in acetyl coA via high energy thioester bond
2 electrons from pyruvate C-C bond transferred to NADH
Why is the function of private dehydrogenase?
Decarboxylates Pyruvate using TPP as a cofactor
What is the function of the peripheral subunit binding domain?
Binds E2 to E1 or E3
What are the two last steps of the PDH complex?
lipoamide undergoes 2 electron reduction to dihydrolipoamide, E3 has redox active disuldue bond thats tightly bound to FAD, passes electron to FAD which get stolen off by NADH
