Michetti F, Donato R
J Neurochem. 1981 May;36(5):1706-11. doi: 10.1111/j.1471-4159.1981.tb00422.x.
Fractionation of isolated brain nuclei previously reacted with (125)I-labelled S-100 showed that most of the specifically bound radioactivity associated with the nuclear membranes and the nucleoli. Labelling of nucleoli, which indicates the entrance of (125)I-labelled S-100 into the nucleus, was observed at 37 percent C, but not at 0-4 percent C. When tested separately for (125)I-labelled S-100 specific binding, both the nuclear membranes and the nucleoli were found to bind (125)I-labelled S-100 in a biphasic manner, the binding displaying a high affinity and a low affinity component, as observed with intact nuclei. However, the binding to nuclear membranes was largely irreversible, while that to nucleoli was fully reversible after any association time.
对先前与（125）I标记的S-100反应的分离脑细胞核进行分级分离，结果显示，大部分特异性结合的放射性与核膜和核仁相关。在37℃观察到核仁标记，这表明（125）I标记的S-100进入了细胞核，但在0-4℃未观察到。当分别测试（125）I标记的S-100特异性结合时，发现核膜和核仁均以双相方式结合（125）I标记的S-100，这种结合表现出高亲和力和低亲和力成分，这与完整细胞核的情况一致。然而，与核膜的结合在很大程度上是不可逆的，而与核仁的结合在任何结合时间后都是完全可逆的。
