Purification and partial characterization of cellular retinoic acid-binding protein from human placenta.
Cellular retinoic acid-binding protein (CRABP) has been purified to homogeneity from human placenta by a series of procedures, including acetone powder extraction, gel filtration on Sephadex G-50, and ion-exchange chromatography on DEAE-cellulose and on SP-Sephadex. Cellular retinol-binding protein (CRBP) was isolated concurrently. CRABP was purified 75,400-fold, based on total soluble acetone powder extract of placenta. The protein is a single polypeptide chain with a molecular mass of 14,600 Da, estimated by sodium dodecyl sulfate (SDS) gel electrophoresis or gel filtration, and has an isoelectric point of 4.78 (apo-CRABP, 4.82). On analysis of absorption and fluorescence spectra, the protein was seen to exhibit an absorption peak at 350 nm, fluorescence excitation maxima at 350 and 370 nm, and a fluorescence emission maximum at 475 nm. Human CRABP was immunologically distinct from human CRBP and serum retinol-binding protein.
D002352:Carrier Proteins / Q000276:immunology / Q000302:isolation & purification*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000276:immunology; D005260:Female; D006801:Humans; D007526:Isoelectric Point; D008970:Molecular Weight; D010920:Placenta / Q000032:analysis*; D011247:Pregnancy; D018168:Receptors, Retinoic Acid; D013050:Spectrometry, Fluorescence; D013053:Spectrophotometry
D002352:Carrier Proteins; D000939:Epitopes; D018168:Receptors, Retinoic Acid