Takase S, Ong D E, Chytil F
Proc Natl Acad Sci U S A. 1979 May;76(5):2204-8. doi: 10.1073/pnas.76.5.2204.
Purified cellular retinol-binding protein (CRBP), a potential mediator of vitamin A action, was found to enable retinol to bind in a specific manner to isolated nuclei from livers of vitamin A deficient rats. Binding was followed after complexing [3H]retinol with CRBP. The binding was specific, saturable, and temperature dependent. CRBP charged with unlabeled retinol or CRBP without retinol diminished binding of radioactivity whereas free retinol did not. No specific binding sites could be detected for free retinol. Purified cellular retinoic acid binding protein (CRABI) complexed with retinoic acid did not diminish the amount of retinol bound to nuclei. Approximately 3 x 10(5) specific binding sites per nucleus could be detected. Fewer binding sites were found in nuclei isolated from livers of control (chow-fed) rats and also from livers of vitamin A-deficient rats 2 hr after refeeding with retinylacetate.
纯化的细胞视黄醇结合蛋白（CRBP）是维生素A作用的潜在介质，它能使视黄醇以特定方式与维生素A缺乏大鼠肝脏分离出的细胞核结合。将[3H]视黄醇与CRBP复合后跟踪结合情况。这种结合具有特异性、可饱和性且依赖温度。负载未标记视黄醇的CRBP或不含视黄醇的CRBP会减少放射性结合，而游离视黄醇则不会。未检测到游离视黄醇的特异性结合位点。与视黄酸复合的纯化细胞视黄酸结合蛋白（CRABI）不会减少与细胞核结合的视黄醇量。每个细胞核可检测到约3×10(5)个特异性结合位点。在从对照（正常饮食喂养）大鼠肝脏以及维生素A缺乏大鼠用视黄基乙酸酯重新喂养2小时后的肝脏中分离出的细胞核中发现的结合位点较少。
