Wiggert B, Bergsma D R, Helmsen R J, Alligood J, Lewis M, Chader G J
Biochim Biophys Acta. 1977 Mar 28;491(1):104-13. doi: 10.1016/0005-2795(77)90045-9.
Specific receptors for retinol are present in the cytosol fraction of corneal epithelium as demonstrated by sucrose density gradient centrifugation. These appear to be (1) protein in nature (2) of small molecular size (2 S) (3) specific for retinol and (4) present in several species. Assuming a receptor molecular weight of 15 000 and a single mole of retinol bound/mole of receptor protein, the association constant value is 5.26-10(7) with deltaG degrees = -8.53 kcal/mol. 2-S receptors are also observed in stroma and endothelium along with another binding species of approximately 8 S. Binding of [3H]retinol in bovine epithelial cytosol can also be demonstrated by disc gel electrophoresis and gel filtration. Immunodiffusion techniques demonstrate that monkey corneal epithelial and stromal cytosol samples do not contain contaminating serum retinol binding-protein.
通过蔗糖密度梯度离心法证明，视黄醇的特异性受体存在于角膜上皮的胞质溶胶部分。这些受体似乎具有以下特点：（1）本质上是蛋白质；（2）分子尺寸小（2S）；（3）对视黄醇具有特异性；（4）存在于多个物种中。假设受体分子量为15000，且每摩尔受体蛋白结合一摩尔视黄醇，则缔合常数为5.26×10⁷，ΔG° = -8.53千卡/摩尔。在基质和内皮中也观察到2S受体以及另一种约8S的结合物种。圆盘凝胶电泳和凝胶过滤也可证明[³H]视黄醇在牛上皮细胞溶质中的结合。免疫扩散技术表明，猴角膜上皮和基质细胞质溶胶样品不含有污染性血清视黄醇结合蛋白。
