EC Number |
Reaction |
Reference |
---|
2.3.1.50 | palmitoyl-CoA + L-serine = CoA + 3-dehydro-D-sphinganine + CO2 |
formation of the external aldimine intermediate |
487175 |
2.3.1.50 | palmitoyl-CoA + L-serine = CoA + 3-dehydro-D-sphinganine + CO2 |
mechanism |
487156, 487174 |
2.3.1.50 | palmitoyl-CoA + L-serine = CoA + 3-dehydro-D-sphinganine + CO2 |
ordered bi-bi mechanism |
-, 487172 |
2.3.1.50 | palmitoyl-CoA + L-serine = CoA + 3-dehydro-D-sphinganine + CO2 |
pyridoxal 5'-phosphate dependent reaction mechanism, key active site residues are His159, Asp231, His234, and Lys265 |
736305 |
2.3.1.50 | palmitoyl-CoA + L-serine = CoA + 3-dehydro-D-sphinganine + CO2 |
the enzyme forms a pyridoxal 5'-phosphate-L-serine-aldimine intermediate during the reaction, His159 plays multiple roles in the reaction mechanism by exploiting the stereochemistry of Dunathans conjecture. His159 promotes both the Claisen-type condensation as an acid catalyst and the protonation at Calpha of the second quinonoid to form the pyridoxal 5'-phosphate-KDS aldimine, spectral analysis, overview |
704483 |
2.3.1.50 | palmitoyl-CoA + L-serine = CoA + 3-dehydro-D-sphinganine + CO2 |
the enzyme forms an external aldimine intermediate, as well as dunathan and quinoid intermediates, and followed by external beta-keto acid intermediate, and finally product quinoid and product external aldimine intermediates, reaction cycle, overview |
-, 704496 |
2.3.1.50 | palmitoyl-CoA + L-serine = CoA + 3-dehydro-D-sphinganine + CO2 |
the enzyme forms an external aldimine intermediate, as well as dunathan and quinoid intermediates, followed by external beta-keto acid intermediate, and finally product quinoid and product external aldimine intermediates, reaction cycle, overview |
704496 |
2.3.1.50 | palmitoyl-CoA + L-serine = CoA + 3-dehydro-D-sphinganine + CO2 |
the reaction proceeds via a key carbanion/quinonoid species and an internal aldimine/PLP-bound form of the enzyme |
735744 |
2.3.1.50 | palmitoyl-CoA + L-serine = CoA + 3-dehydro-D-sphinganine + CO2 |
the reaction proceeds via several intermediate states, the pyridoxal 5'-phosphate cofactor binds to an active site lysine residue as an internal aldimine/Schiffs base (I). The L-serine displaces the lysine residue (Lys265) to form the PLP-L-serine external aldimine (II). Deprotonation of II gives a carbanion/quinonoid species (III) which condenses in a Claisen-like manner with the acyl-CoA thioester substrate to form a PLP-beta-keto acid, which then decarboxylates to generate the PLP-KDS product quinonoid (IV). This then reprotonates to form PLP-KDS aldimine (V) which is finally displaced by Lys265. The step releasing CoA and CO2 and producing the quinonoid intermediate species is irreversible. Interaction between the hydroxyl group of the L-serine substrate and the 5'-phosphate group of pyridoxal 5'-phosphate occurs in the formation of the external aldimine II, overview |
735932 |
2.3.1.50 | palmitoyl-CoA + L-serine = CoA + 3-dehydro-D-sphinganine + CO2 |
using 1HNMR the exchange of the alpha-proton of L-serine with the solvent in the presence and absence of S-(2- oxoheptadecyl)-CoA, the structural analogue of palmitoyl-CoA is investagated. Results demonstrate the presence of substrate synergism, in which the alpha-proton of L-serine is activated by the binding of the second substrate palmitoyl-CoA |
687795 |