all-trans-retinyl-ester hydrolase, 11-cis retinol forming activity
Definition
Target type: molecularfunction
Catalysis of the reaction: H2O + all-trans-retinyl ester = 11-cis-retinol + fatty acid. [RHEA:31771]
All-trans-retinyl-ester hydrolase, 11-cis retinol forming activity, is a crucial enzyme in the visual cycle, responsible for the regeneration of 11-cis retinal, the light-absorbing chromophore of rhodopsin. This enzyme catalyzes the hydrolysis of all-trans-retinyl esters, primarily all-trans-retinyl palmitate, to release all-trans-retinol. All-trans-retinol is then isomerized to 11-cis-retinol by an isomerase enzyme. Finally, 11-cis-retinol is oxidized to 11-cis-retinal, which binds to opsin to regenerate rhodopsin. This entire process is essential for light perception and vision. The molecular function of this enzyme involves:
1. **Binding of all-trans-retinyl esters:** The enzyme binds to all-trans-retinyl esters, typically all-trans-retinyl palmitate, in its active site.
2. **Hydrolysis of the ester bond:** The enzyme utilizes a catalytic mechanism to hydrolyze the ester bond, releasing all-trans-retinol and a fatty acid, typically palmitic acid.
3. **Release of all-trans-retinol:** The enzyme releases all-trans-retinol from its active site, making it available for isomerization.
This enzymatic activity is critical for maintaining the visual cycle and ensuring proper light perception.'
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Proteins (2)
| Protein | Definition | Taxonomy |
|---|---|---|
| Retinoid isomerohydrolase | [no definition available] | Bos taurus (cattle) |
| Retinoid isomerohydrolase | A retinal pigment epithelium-specific 65 kDa protein that is encoded in the genome of chicken. [PRO:DNx] | Gallus gallus (chicken) |
Compounds (2)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| retinylamine | retinylamine: structure | ||
| phenyl-n-tert-butylnitrone | phenyl-N-tert-butylnitrone: a spin-trapping agent |