Bertin Aurélie, Leforestier Amélie, Durand Dominique, Livolant Françoise
Laboratoire de Physique des Solides, CNRS UMR 8502, Bât 510, Université Paris-Sud, 91405 Orsay.
Biochemistry. 2004 Apr 27;43(16):4773-80. doi: 10.1021/bi036210g.
The goal of this work was to test the role of the histone tails in the emergence of attractive interactions between nucleosomes above a critical salt concentration that corresponds to the complete tail extension outside the nucleosome [Mangenot, S., et al (2002) Biophys. J. 82, 345-356; Mangenot, S., et al (2002) Eur. Phys. J. E 7, 221-231]. Small angle X-ray scattering experiments were performed in parallel with intact and trypsin tail-deleted nucleosomes with 146 +/- 3 bp DNA. We varied the monovalent salt concentration from 10 to 300 monovalent salt concentration and followed the evolution of (i) the second virial coefficient that characterizes the interactions between particles and (ii) the conformation of the particle. The attractive interactions do not emerge in the absence of the tails, which validates the proposed hypothesis.
这项工作的目标是测试组蛋白尾巴在核小体之间出现吸引相互作用中的作用，这种相互作用出现在高于临界盐浓度时，该临界盐浓度对应于核小体外部组蛋白尾巴的完全伸展[Mangenot, S., 等人(2002年)《生物物理杂志》82卷，345 - 356页；Mangenot, S., 等人(2002年)《欧洲物理杂志E》7卷，221 - 231页]。采用小角X射线散射实验，同时对含有146 ± 3个碱基对DNA的完整核小体和经胰蛋白酶处理去除尾巴的核小体进行研究。我们将单价盐浓度从10变化到300，同时跟踪(i)表征颗粒间相互作用的第二维里系数以及(ii)颗粒构象随盐浓度的变化情况。在没有尾巴的情况下不会出现吸引相互作用，这验证了所提出的假设。
