EC Number   |
Reaction |
Reference |
|---|
   4.2.1.112 | acetaldehyde = acetylene + H2O |
- |
- |
| 4.2.1.112 | acetaldehyde = acetylene + H2O |
acetylene hydratase harbors two pyranopterins bound to tungsten, and a [4Fe-4S] cluster. Tungsten is coordinated by four dithiolene sulfur atoms, one cysteine sulfur, and one oxygen ligand. The enzyme activity requires a strong reductant suggesting (IV) as the active oxidation state. Two different types of reaction pathways have been proposed, the reaction does not involve a net electron transfer |
748243 |
| 4.2.1.112 | acetaldehyde = acetylene + H2O |
acetylene hydratase harbors two pyranopterins bound to tungsten, and a [4Fe-4S] cluster. Tungsten is coordinated by four dithiolene sulfur atoms, one cysteine sulfur, and one oxygen ligand. The enzyme activity requires a strong reductant suggesting (IV) as the active oxidation state. Two different types of reaction pathways have been proposed, the reaction does not involve a net electron transfer. The nature of the oxygen ligand of the W center in the enzyme is crucial to formulate a reaction mechanism. Residue Asp13 is catalytically important because it activates the oxygen atom for the addition to the C-C triple bond. Reaction mechanism analysis, overview |
748431 |
| 4.2.1.112 | acetaldehyde = acetylene + H2O |
acetylene hydratase harbors two pyranopterins bound to tungsten, and a [4Fe-4S] cluster. Tungsten is coordinated by four dithiolene sulfur atoms, one cysteine sulfur, and one oxygen ligand. The enzyme activity requires a strong reductant suggesting (IV) as the active oxidation state. Two different types of reaction pathways have been proposed, the reaction does not involve a net electron transfer. The nature of the oxygen ligand of the W center in the enzyme is crucial to formulate a reaction mechanism. Residue Asp13 is catalytically important because it activates the oxygen atom for the addition to the C-C triple bond. Representation of the five-step catalytic cycle, with Asp13 acting as a key player in the mechanism, and W binding and activating C2H2, and providing electrostatic stabilization to the transition states and intermediates |
748243 |
| 4.2.1.112 | acetaldehyde = acetylene + H2O |
active site channel structure and detailed catalytic mechanism |
670710 |
| 4.2.1.112 | acetaldehyde = acetylene + H2O |
active-site access, active-site architecture, and reaction mechanism, overview |
-, 715374 |
| 4.2.1.112 | acetaldehyde = acetylene + H2O |
active-site modeling and reaction mechanism involving direct coordination of the substrate to the tungsten ion, followed by a nucleophilic attack by a water molecule concerted with a proton transfer to a second-shell aspartate, which then reprotonates the substrate. A tungsten-bound hydroxide plays the key role performed by Asp13 in the enzyme, rate-limiting proton transfer step from Asp13 residue to the C2 center of the vinyl anion |
713603 |
| 4.2.1.112 | acetaldehyde = acetylene + H2O |
active-site modeling and reaction mechanism, detailed overview. The mechanism starts with a ligand exchange step, in which the acetylene substrate displaces the tungsten-bound water molecule and binds to the metal in an eta2 fashion. Then the nucleophilic attack takes place nearly perpendicularly to the W-C-C plane, concerted nucleophilic attack-proton transfer transition state and the resulting vinyl anion intermediate, W=C=CH2 vinylidene intermediate, overview. To complete the reaction, the vinyl alcohol now needs only to tautomerize to acetaldehyde. At this point, the vinyl alcohol can be released and the interconversion can take place outside the active site. Alternative mechanisms, overview |
716769 |
| 4.2.1.112 | acetaldehyde = acetylene + H2O |
reaction mechanism involving molybdenum-cofactor and tungsten/iron-sulfur cluster, structure-function modeling, overview |
669039 |
