Cytosol oestrogen receptor of lactating mammary gland. Effect of heparin on the aggregation of the receptor and interaction of the receptor with heparin-Sepharose.
作者信息
Auricchio F, Rotondi A, Sampaolo P, Schiavone E
出版信息
Biochem J. 1978 Apr 1;171(1):137-41. doi: 10.1042/bj1710137.
An oestrogen receptor is present in low-salt cytosol of the mammary gland of lactating mice as a large aggregate; it is excluded from gel matrix when filtered on a Sephadex G-200 column and sediments at 7S in sucrose gradients. After incubation of cytosol with heparin, the receptor is dissociated. On a Sephadex G-200 column, it is included in the gel matrix and eluted as a protein with mol.wt. 260000 and a Stokes radius of 6.8nm; it sediments at 6S in sucrose gradients. 2. Dissociation of the mammary-gland cytosol oestrogen receptor seems to be the result of interaction of the oestrogen-receptor complex with heparin. This receptor interacts with heparin covalently bound to Sepharose, thereafter sedimenting at 6S. By using this interaction, the cytosol receptor was purified 200-fold compared with the homogenate, with a yield of 70%. 3. The cytosol receptor that was not incubated or was incubated with heparin was much smaller during sucrose-gradient centrifugation than during gel filtration. This discrepancy can be explained by pressure-induced dissociation during high-speed centrifugation. This possibility is supported by the decrease in the sedimentation coefficient of the receptor with increased duration of centrifugation.
摘要
雌激素受体以大聚集体形式存在于泌乳小鼠乳腺的低盐胞质溶胶中；在Sephadex G - 200柱上过滤时，它被排除在凝胶基质之外，在蔗糖梯度中沉降系数为7S。用肝素孵育胞质溶胶后，受体解离。在Sephadex G - 200柱上，它被包含在凝胶基质中，并作为分子量为260000、斯托克斯半径为6.8nm的蛋白质被洗脱；在蔗糖梯度中沉降系数为6S。2. 乳腺胞质溶胶雌激素受体的解离似乎是雌激素 - 受体复合物与肝素相互作用的结果。该受体与共价结合到琼脂糖上的肝素相互作用，此后沉降系数为6S。利用这种相互作用，与匀浆相比，胞质溶胶受体纯化了200倍，产率为70%。3. 在蔗糖梯度离心过程中，未孵育或与肝素孵育的胞质溶胶受体比在凝胶过滤过程中要小得多。这种差异可以通过高速离心过程中压力诱导的解离来解释。随着离心时间延长，受体沉降系数降低，这支持了这种可能性。
