一种由组蛋白H2A C末端尾巴水解切割产生的极其稳定的镍（II）配合物。

An extremely stable Ni(II) complex derived from the hydrolytic cleavage of the C-terminal tail of histone H2A.

作者信息

Mylonas Marios, Plakatouras John C, Hadjiliadis Nick, Papavasileiou Konstantinos D, Melissas Vasilios S

机构信息

Department of Chemistry, University of Ioannina, GR 451 10 Ioannina, Greece.

出版信息

J Inorg Biochem. 2005 Feb;99(2):637-43. doi: 10.1016/j.jinorgbio.2004.11.020.

DOI:10.1016/j.jinorgbio.2004.11.020

PMID:15621298

Abstract

The C-terminal blocked tetrapeptides SHHK- and SAHK-, which represent the fragments produced from the hydrolysis of the hexapeptides' -TASHHK-, -TESHHK-, and -TESAHK- complexes with Ni(II), were synthesized and their interactions with Ni(II) ions were studied potentiometrically and spectroscopically. Both tetrapeptides interact strongly with Ni(II) ions leading to square-planar complexes with 4N {NH(2),2N(-),N(im)} coordination. The stability of the Ni-SHHK- complex is about 2 orders of magnitude higher than the Ni-SAHK- complex. Spectroscopic evidence and theoretical predictions suggest the positioning of the free imidazole ring, in the Ni-SHHK- complex, above the coordination plane, explaining the extra stability of the complex.

摘要

C 端封闭的四肽 SHHK-和 SAHK-是六肽-TASHHK-、-TESHHK-和-TESAHK-与 Ni(II)络合物水解产生的片段，合成了这两种四肽，并通过电位滴定法和光谱法研究了它们与 Ni(II)离子的相互作用。两种四肽都与 Ni(II)离子强烈相互作用，形成具有 4N{NH(2),2N(-),N(im)}配位的平面正方形络合物。Ni-SHHK-络合物的稳定性比 Ni-SAHK-络合物高约 2 个数量级。光谱证据和理论预测表明，在 Ni-SHHK-络合物中，游离咪唑环位于配位平面上方，这解释了该络合物额外的稳定性。