Interaction between prealbumin and retinol-binding protein studied by affinity chromatography, gel filtration and two-phase partition.
The interaction between prealbumin and apo or holo retinol-binding proteins has been studied by affinity chromatography, gel filtration and two-phase partition. At physiological ionic strength apo and holo retinol-binding protein form 1:1 molar complexes with prealbumin. Mean dissociation constants for the prealbumin compex with apo retinol-binding protein and holo retinol-binding protein with all-trans retinol, retinoic acid, retinal and retinyl acetate were calculated from the partition data as 0.33 +/- 0.11 x 10(-6) M and 0.075 +/- 0.015 x 10(-6) M respectively (mean +/- S.E.M.). The difference was statistically significant. Quantitative data on the amount of retinol, retinol-binding protein and prealbumin in plasma and urine were in good agreement with the ratio of the dissociation constants for the complexes of apo and holo retinol-binding proteins with prealbumin as determined in the partition experiment. The magnitude of the dissociation constants was compatible with previously published data on the turnover of retinol-binding protein.
D000368:Aged; D001059:Apoproteins; D001665:Binding Sites; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D006801:Humans; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D011228:Prealbumin / Q000378:metabolism / Q000652:urine; D012177:Retinol-Binding Proteins / Q000097:blood / Q000652:urine; D054839:Retinol-Binding Proteins, Plasma; D012709:Serum Albumin; D012995:Solubility; D014801:Vitamin A / Q000097:blood / Q000652:urine
D001059:Apoproteins; D011228:Prealbumin; D012177:Retinol-Binding Proteins; D054839:Retinol-Binding Proteins, Plasma; D012709:Serum Albumin; D014801:Vitamin A