Biosynthesis of 11-cis-retinoids and retinyl esters by bovine pigment epithelium membranes

Journal Article · Tue Dec 01 00:00:00 EST 1987 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00398a059· OSTI ID:5357544

Fulton, B S; Rando, R R

Previously, we have shown that retina/pigment epithelium membranes from the amphibian can synthesize 11-cis-retinoids from added all-trans-retinol. The activity was largely localized to the pigment epithelium. Here it is shown that, in the bovine system, the activity resides exclusively in the membranes of the pigment epithelium. Subcellular fractionation does not reveal a particular organelle where the activity resides. Washed bovine pigment epithelium membranes, which are devoid of retinoid redox activity, convert added all-trans-retinol to a mixture of 11-cis-retinol and its palmitate ester. all-trans-Retinal and all-trans-retinyl palmitate are not converted into 11-cis-retinoids by the membranes. The membranes show substantial ester synthetase activity, producing large amounts of all-trans-retinyl palmitate. Diverse chemical reagents, such as ethanol, hydroxylamine, and p-(hydroxymercuri)benzoate, inhibit both ester synthetase and isomerase activities in a roughly parallel fashion, suggesting a possible functional linkage between the two activities.

• Research Organization: Harvard Medical School, Boston, MA (USA)
• OSTI ID: 5357544
• Journal Information: Biochemistry; (United States), Vol. 26:24
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ISOMERASES
ENZYME ACTIVITY
LIGASES
RETINOIC ACID
BIOSYNTHESIS
CATTLE
CELL MEMBRANES
EPITHELIUM
ESTERS
PIGMENTS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VITAMIN A
ANIMAL TISSUES
ANIMALS
BODY
CARBOXYLIC ACID ESTERS
CELL CONSTITUENTS
DOMESTIC ANIMALS
ENZYMES
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MEMBRANES
ORGANIC COMPOUNDS
RUMINANTS
SYNTHESIS
TISSUES
VERTEBRATES
VITAMINS
550201* - Biochemistry- Tracer Techniques