Identification of the endogenous retinoids associated with three cellular retinoid-binding proteins from bovine retina and retinal pigment epithelium

J Biol Chem. 1982 Nov 25;257(22):13329-33.

Abstract

The endogenous retinoids associated with three cellular retinoid-binding proteins from bovine retina and retinal pigment epithelium have been identified by their spectral characteristics and their co-migration with authentic retinoids on high performance liquid chromatography. All-trans-retinol is the only retinoid associated with the cellular retinol-binding protein from retina and retinal pigment epithelium. The saturation of the binding site with native ligand is 0.95 +/- 0.05 mol of retinoid/mol of protein for cellular retinol-binding protein purified from frozen and fresh retina and retinal pigment epithelium. All-trans-retinoic acid has been identified as the endogenous ligand associated with the cellular retinoic acid-binding protein of cattle retina. The saturation of the binding site of cellular retinoic acid-binding protein from frozen and fresh retina (the protein is absent in extracts of retinal pigment epithelium) is about 0.2 mol of retinoid/mol of protein, probably a minimum value due to losses of the ligand. Retinoic acid has not been detected previously in retina. Cellular retinaldehyde-binding protein from retina purifies with two endogenous ligands which cochromatograph on high performance liquid chromatography with 11-cis-retinaldehyde and 11-cis-retinol and occur in a ratio of approximately 3:1, respectively. The binding site of cellular retinaldehyde-binding protein from frozen retina is nearly fully occupied with these two ligands (saturation greater than 0.9 mol of retinoids/mol of protein). In contrast, purified cellular retinaldehyde-binding protein from retinal pigment epithelium carries only 11-cis-retinaldehyde as an endogenous ligand. The saturation of the binding site with this ligand is greater than 0.95.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Carrier Proteins / metabolism
  • Cattle
  • Pigment Epithelium of Eye / metabolism
  • Receptors, Retinoic Acid
  • Retina / metabolism*
  • Retinaldehyde / metabolism
  • Retinol-Binding Proteins / metabolism
  • Retinol-Binding Proteins, Cellular
  • Spectrophotometry, Ultraviolet
  • Vitamin A / analogs & derivatives*
  • Vitamin A / metabolism

Substances

  • 11-cis-retinal-binding protein
  • Carrier Proteins
  • Receptors, Retinoic Acid
  • Retinol-Binding Proteins
  • Retinol-Binding Proteins, Cellular
  • Vitamin A
  • Retinaldehyde