EC Number   |
Reaction |
Reference |
|---|
    2.6.1.42 | L-leucine + 2-oxoglutarate = 4-methyl-2-oxopentanoate + L-glutamate |
bibi ping-pong mechanism. For good 2-oxoacid substrates, release of 2-oxoglutarate is much slower than release of the product amino acid during the transamination reaction |
738209 |
| 2.6.1.42 | L-leucine + 2-oxoglutarate = 4-methyl-2-oxopentanoate + L-glutamate |
branched-chain amino acid + 2-oxoglutarate = corresponding keto acid + L-glutamate, also acts on L-isoleucine and L-valine. Different from EC 2.6.1.66 valine-pyruvate transaminase |
- |
| 2.6.1.42 | L-leucine + 2-oxoglutarate = 4-methyl-2-oxopentanoate + L-glutamate |
first transaminase half-reaction via internal aldimine, external aldimine, ketimine, and pyridoxamine (PMP)-bound form |
-, 758848 |
| 2.6.1.42 | L-leucine + 2-oxoglutarate = 4-methyl-2-oxopentanoate + L-glutamate |
MtIlvE displays a ping-pong kinetic mechanism. The phosphate ester of the PLP cofactor, and the alpha-amino group from L-glutamate and the active site Lys204, play roles in acid-base catalysis and binding, respectively. An intrinsic primary kinetic isotope effect is identified for the alpha-C-H bond cleavage of L-glutamate. Large solvent kinetic isotope effect values for the ping and pong half-reactions are also identified |
-, 758794 |
| 2.6.1.42 | L-leucine + 2-oxoglutarate = 4-methyl-2-oxopentanoate + L-glutamate |
reaction mechanism of aminotransferases via external aldimine, quinonoid intermediate, ketimine, and carbinolamine, overview |
-, 758768 |
| 2.6.1.42 | L-leucine + 2-oxoglutarate = 4-methyl-2-oxopentanoate + L-glutamate |
transamination functions through a ping pong kinetic mechanism involving two half-reactions, characterised by the interconversion of its PLP and PMP (pyridoxamine) form. In the first half reaction, binding of the BCAA triggers transaldimination releasing the active lysine and an external aldimine is formed between substrate and the PLP cofactor. The lysine residue is the catalytic base in the next step, a 1,3-prototropic shift that converts the external aldimine into a ketamine intermediate. Here, a proton is abstracted from the ?-carbon of the substrate amino acid and subsequent re-protonation of the aldehyde carbon of the coenzyme yields the ketamine. The final step in the first half-reaction is the hydrolysis of the ketamine to give the PMP form of the enzyme and an 2-oxo acid. The second half-reaction is the reversal of the first half-reaction with a different 2-oxo acid. The committed step in the complete oxidation of the BCAA is catalysed by the BCKD generating acyl CoAs |
758657 |
| 2.6.1.42 | L-leucine + 2-oxoglutarate = 4-methyl-2-oxopentanoate + L-glutamate |
transamination functions through a ping pong kinetic mechanism involving two half-reactions, characterised by the interconversion of its PLP and PMP (pyridoxamine) form. In the first half reaction, binding of the BCAA triggers transaldimination releasing the active lysine and an external aldimine is formed between substrate and the PLP cofactor. The lysine residue is the catalytic base in the next step, a 1,3-prototropic shift that converts the external aldimine into a ketamine intermediate. Here, a proton is abstracted from the alpha-carbon of the substrate amino acid and subsequent re-protonation of the aldehyde carbon of the coenzyme yields the ketamine. The final step in the first half-reaction is the hydrolysis of the ketamine to give the PMP form of the enzyme and an 2-oxo acid. The second half-reaction is the reversal of the first half-reaction with a different 2-oxo acid. The committed step in the complete oxidation of the BCAA is catalysed by the BCKD generating acyl CoAs. During transamination, the BCAA substrate binds to the PLP cofactor at the bottom of the active site and donates its nitrogen to PLP-BCATm |
758657 |
