Retinol-binding protein characterization

Transthyretin amyloidosis (also called familial amyloid polyneuropathy) is an autosomal dominant syndrome characterized by peripheral neuropathy. This disease results from one of five mutations identified thus far in the gene for transthyretin. Transthyretin is also called prealbumin (although it has no structural relationship to albumin) because it migrates ahead of albumin in standard electrophoresis at pH 8.6. Transthyretin is synthesized in the liver and is a normal plasma protein with a concentration of 20-40 mg/dL. It transports thyroxine and retinol binding protein (Chapter 38). The concentration of transthyretin is significantly decreased in malnutrition and plasma levels are diagnostic of disorders of malnutrition (Chapter 17). 

The predicted chylomicron retinyl-d4 ester curve is characterized by a sharp peak similar to that of the /3-carotene-dg, again in accord with the expected rapid clearance of chylomicrons foUowing a meal. The predicted plasma retinol-binding protein-retinol-d4 curve shows an initial rise and fall, then a sustained level of retinol-d4 after the /3-carotene-dg dose. This is very similar in shape to that seen when the same subject ingested retinyl-d4 acetate in a previous experiment (Song et oL, 1995). The sustained level of retinol-d4 is a result of the slow release of retinoid into the plasma from... 

Muto, Y., Goodman, D-W.S. Vitamin A transport in rat plasma isolation and characterization of retinol-binding protein. J. biol. Chem. 247, 2533-2541 (1972)... 

Ong, D. E. (1984) A novel retinol-binding protein from rat-purification and partial characterization, J Biol Chem 259,1476-1482... 

Schaefer, W. H, Kakkad, B., Crow, J. A, Blair, I A, and Ong, D E. (1989) Purification, primary structure characterization, and cellular-distribution of 2 forms of cellular retinol-binding protein, type-II from adult-rat small-intestme. J Biol. Chem. 264,4212-4221... 

Inagami, S and Ong, D. E. (1992) Purification and partial characterization of cellular retinol-binding protein, type-2, from human small-mtestine. J Nutr 122, 450-456... 

The peculiar spectral properties of CRBP-bound retinol and RME are indicative of specific ligand-protein interactions (see Fig. 2) Instead, other holo-retinoid-binding proteins exhibit less characteristic spectra. For example the absorption spectrum of the complex of retinol with plasma retinol-binding protein (RBP) is characterized by a single, well-shaped peak centered at approx 328 nm On the other hand, the absorption spectra of some CRBP-bound retinoids, like CRBP-bound a l-trans retinal (12,13), do not resemble those of CRBP-bound retinol and RME. 

Matsuo T, Matsuo N (1988) Characterization of retinol-binding protein in familial hypo-retinol-binding proteinemia. Jpn J Ophthalmol 32 379-384... 

Vogel S, Mendelsohn CL, Mertz JR, Piantedosi R, Waldburger C, Gottesman ME, and BlanerWS (2001) Characterization ofa new member of the fatty acid-binding protein family that binds all-trans-retinol. Journal of Biological Chemistry 276, 1353-60. 

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