Properties of retinal-oxidizing enzyme activity in rat kidney.
An enzyme activity which converts retinal to retinoic acid was found in the cytosol of rat kidney. The oxidation of retinal was pH-, temperature-, time- and protein-dependent. Under the assay conditions employed, the oxidase activity had an apparent Km of 125 microM toward all-trans retinal. n-Propylgallate, butylated hydroxytoluene and quinacrine inhibited the reaction. The inhibition caused by quinacrine can be partly reversed by FAD. p-Hydroxymercuribenzoate, a sulfhydryl cross-linking agent, was a potent inhibitor. 4'-(9-Acridinylamino)methanesulfon-anisidide, an inhibitor of aldehyde oxidase, inhibited the reaction by 77% at a concentration of 3 mM. All-trans retinal reversed the inhibition caused by acetaldehyde and 2-aminobenzaldehyde. Retinol inhibited the reaction, but retinoic acid did not. The specific activity of the enzyme was increased by vitamin A deficiency. These data indicate that retinal-oxidizing enzyme activity found in the kidney is a sulfhydryl flavoprotein and its activity is dependent on the vitamin A levels of the tissues.
Bhat
P V
PV
Clinical Research Institute of Montreal, Quebec, Canada.
Poissant
L
L
Lacroix
A
A
D000818:Animals; D003600:Cytosol / Q000201:enzymology; D005182:Flavin-Adenine Dinucleotide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007668:Kidney / Q000201:enzymology*; D007700:Kinetics; D008297:Male; D010084:Oxidation-Reduction; D011435:Propyl Gallate / Q000494:pharmacology; D011796:Quinacrine / Q000494:pharmacology; D051381:Rats; D012172:Retinaldehyde / Q000378:metabolism*; D012176:Retinoids / Q000378:metabolism*; D013696:Temperature; D013997:Time Factors; D014212:Tretinoin / Q000378:metabolism; D014802:Vitamin A Deficiency / Q000201:enzymology
D012176:Retinoids; D005182:Flavin-Adenine Dinucleotide; D014212:Tretinoin; D011435:Propyl Gallate; D011796:Quinacrine; D012172:Retinaldehyde