Cytoplasmic glucocorticoid binding proteins in bone cells.
Cytoplasmic glucocorticoid binding proteins in bone cells.
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骨细胞中的细胞质糖皮质激素结合蛋白。
DOI：
10.1210/endo-96-1-29
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发表时间：
1975
期刊：
影响因子：
4.8
通讯作者：
P. Stern
中科院分区：
文献类型：
--
作者：
D. Feldman;R. Dziak;R. Koehler;P. Stern
用酶消化法分离胎鼠颅骨骨细胞，研究~ 3 H-地塞米松（~ 3 H-DM）与骨细胞胞浆的结合。一个高亲和力的糖皮质激素结合蛋白类似于其他靶组织中描述的。Scatchard分析揭示了一类结合位点，3 H-DM（OC）的表观解离常数为7 x 10- 9 M，结合位点浓度为0.11 pmoles/mg胞质溶胶蛋白。每个细胞的细胞质结合位点的数量计算为6，000，这可能是低估，因为内源性类固醇占据了一些位点。结合位点在自然界中表现为蛋白质，因为与链霉蛋白酶孵育破坏了100%的结合。在利用骨胞质溶胶作为供体和肝细胞核作为受体的重建系统中证明了核转移。竞争性结合分析显示，皮质酮是相当于DM的结合亲和力，孕酮是75%的有效DM。醛固酮和SC-26304（螺内酯类似物）分别具有1
The binding of 3H-dexamethasone (3H-DM) was studied in the cytoplasmic fraction of bone cells isolated from fetal rat calvaria by enzymatic digestion. An high-affinity glucocorticoid binding protein resembling those described in other target tissues was demonstrated. Scatchard analysis revealed a single class of binding sites with an apparent dissociation constant for 3H-DM (0C) of 7 x 10-9M and a concentration of binding sites of 0.11 pmoles/mg cytosol protein. The number of cytoplasmic binding sites per cell was calculated at 6,000 which is probably an underestimate due to occupancy of some sites by endogenous steroids. The binding sites appeared protein in nature since incubation with pronase destroyed 100% of the binding. Nuclear transfer was demonstrated in a reconstituted system utilizing bone cytosol as donor and liver nuclei as the acceptor. Competitive binding analysis revealed corticosterone to be equivalent to DM in binding affinity; progesterone was 75% as potent as DM. Aldosterone and SC-26304 (a spirolactone analogue) had, respectively, 1