title: Aromatic lipophilic spin traps effectively inhibit RPE65 isomerohydrolase activity.
abstract: We previously showed that RPE65 does not specifically produce 11-cis-retinol only but also 13-cis-retinol, supporting a carbocation or radical cation mechanism of isomerization. The intrinsic properties of conjugated polyene chains result in facile formation of radical cations in oxidative conditions. We hypothesized that such radical intermediates, if involved in the mechanism of RPE65, could be stabilized by spin traps. We tested a variety of hydrophilic and lipophilic spin traps for their ability to inhibit RPE65 isomerohydrolase activity. We found that the aromatic lipophilic spin traps such as N-tert-butyl-α-phenylnitrone (PBN), 2,2-dimethyl-4-phenyl-2H-imidazole-1-oxide (DMPIO), and nitrosobenzene (NB) strongly inhibit RPE65 isomerohydrolase activity in vitro.
authors: LRCMB, NEI, National Institutes of Health, Bethesda, Maryland 20892, United States.
authors: Eugenia
authors: E
authors: Poliakov
authors: Toral
authors: T
authors: Parikh
authors: Michael
authors: M
authors: Ayele
authors: Stephanie
authors: S
authors: Kuo
authors: Preethi
authors: P
authors: Chander
authors: Susan
authors: S
authors: Gentleman
authors: T Michael
authors: TM
authors: Redmond
mesh_terms: D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002460:Cell Line; D004578:Electron Spin Resonance Spectroscopy; D005136:Eye Proteins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D013113:Spin Labels; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase
chemical_list: D002352:Carrier Proteins; D005136:Eye Proteins; D013113:Spin Labels; D019745:cis-trans-Isomerases; D000099178:Retinoid Isomerohydrolase