8doc

Crystal structure of RPE65 in complex with compound 16e and palmitateCrystal structure of RPE65 in complex with compound 16e and palmitate

Structural highlights

8doc is a 1 chain structure with sequence from Bos taurus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.1Å
Ligands:	, , , ,
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

RPE65_BOVIN Plays important roles in the production of 11-cis retinal and in visual pigment regeneration. The soluble form binds vitamin A (all-trans-retinol), making it available for LRAT processing to all-trans-retinyl ester. The membrane form, palmitoylated by LRAT, binds all-trans-retinyl esters, making them available for IMH (isomerohydrolase) processing to all-cis-retinol. The soluble form is regenerated by transferring its palmitoyl groups onto 11-cis-retinol, a reaction catalyzed by LRAT. The enzymatic activity is linearly dependent of the expression levels and membrane association.^[1] ^[2] ^[3]

Publication Abstract from PubMed

In the eye, the isomerization of all-trans-retinal to 11-cis-retinal is accomplished by a metabolic pathway termed the visual cycle that is critical for vision. RPE65 is the essential trans-cis isomerase of this pathway. Emixustat, a retinoid-mimetic RPE65 inhibitor, was developed as a therapeutic visual cycle modulator and used for the treatment of retinopathies. However, pharmacokinetic liabilities limit its further development including: (1) metabolic deamination of the gamma-amino-alpha-aryl alcohol, which mediates targeted RPE65 inhibition, and (2) unwanted long-lasting RPE65 inhibition. We sought to address these issues by more broadly defining the structure-activity relationships of the RPE65 recognition motif via the synthesis of a family of novel derivatives, which were tested in vitro and in vivo for RPE65 inhibition. We identified a potent secondary amine derivative with resistance to deamination and preserved RPE65 inhibitory activity. Our data provide insights into activity-preserving modifications of the emixustat molecule that can be employed to tune its pharmacological properties.

Tuning the Metabolic Stability of Visual Cycle Modulators through Modification of an RPE65 Recognition Motif.,Bassetto M, Zaluski J, Li B, Zhang J, Badiee M, Kiser PD, Tochtrop GP J Med Chem. 2023 Jun 22;66(12):8140-8158. doi: 10.1021/acs.jmedchem.3c00461. Epub , 2023 Jun 6. PMID:37279401^[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Jin M, Li S, Moghrabi WN, Sun H, Travis GH. Rpe65 is the retinoid isomerase in bovine retinal pigment epithelium. Cell. 2005 Aug 12;122(3):449-59. PMID:16096063 doi:10.1016/j.cell.2005.06.042
↑ Kiser PD, Golczak M, Lodowski DT, Chance MR, Palczewski K. Crystal structure of native RPE65, the retinoid isomerase of the visual cycle. Proc Natl Acad Sci U S A. 2009 Oct 13;106(41):17325-30. Epub 2009 Oct 5. PMID:19805034
↑ Golczak M, Kiser PD, Lodowski DT, Maeda A, Palczewski K. Importance of membrane structural integrity for RPE65 retinoid isomerization activity. J Biol Chem. 2010 Mar 26;285(13):9667-82. Epub 2010 Jan 25. PMID:20100834 doi:10.1074/jbc.M109.063941
↑ Bassetto M, Zaluski J, Li B, Zhang J, Badiee M, Kiser PD, Tochtrop GP. Tuning the Metabolic Stability of Visual Cycle Modulators through Modification of an RPE65 Recognition Motif. J Med Chem. 2023 Jun 22;66(12):8140-8158. PMID:37279401 doi:10.1021/acs.jmedchem.3c00461

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OCA

[1] Jin M, Li S, Moghrabi WN, Sun H, Travis GH. Rpe65 is the retinoid isomerase in bovine retinal pigment epithelium. Cell. 2005 Aug 12;122(3):449-59. PMID:16096063 doi:10.1016/j.cell.2005.06.042

[2] Kiser PD, Golczak M, Lodowski DT, Chance MR, Palczewski K. Crystal structure of native RPE65, the retinoid isomerase of the visual cycle. Proc Natl Acad Sci U S A. 2009 Oct 13;106(41):17325-30. Epub 2009 Oct 5. PMID:19805034

[3] Golczak M, Kiser PD, Lodowski DT, Maeda A, Palczewski K. Importance of membrane structural integrity for RPE65 retinoid isomerization activity. J Biol Chem. 2010 Mar 26;285(13):9667-82. Epub 2010 Jan 25. PMID:20100834 doi:10.1074/jbc.M109.063941

[4] Bassetto M, Zaluski J, Li B, Zhang J, Badiee M, Kiser PD, Tochtrop GP. Tuning the Metabolic Stability of Visual Cycle Modulators through Modification of an RPE65 Recognition Motif. J Med Chem. 2023 Jun 22;66(12):8140-8158. PMID:37279401 doi:10.1021/acs.jmedchem.3c00461

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