Interaction between Histidine and Zn(II) Metal Ions over a Wide pH as Revealed by Solid-State NMR Spectroscopy and DFT Calculations

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• 作者：Lei Zhou ; Shenhui Li ; Yongchao Su ; Xianfeng Yi ; Anmin Zheng ; Feng Deng
• 刊名：The Journal of Physical Chemistry B
• 出版年：2013
• 出版时间：August 1, 2013
• 年：2013
• 卷：117
• 期：30
• 页码：8954-8965
• 全文大小：627K
• 年卷期：v.117,no.30(August 1, 2013)
• ISSN：1520-5207

文摘

The interactions between histidine and metal species play essential roles in a wide range of important biological processes including enzymes catalysis and signal transduction. In this work, solid-state NMR techniques were employed to determine the interaction between histidine and Zn(II) from pH 3.5 to 14. 2D homo- and heteronuclear correlation NMR experiments were utilized to extract the ¹H, ¹³C, and ¹⁵N chemical shifts in various histidine鈥揨n(II) binding complexes. Several histidine鈥揨n(II) binding models were proposed on the basis of experimental results as well as DFT theoretical calculations. No direct interaction could be found between biprotonated histidine and Zn(II) at acidic pH. At pH 7.5, one zinc ion could be hexa-coordinated with two histidine molecules on C鈥? N_伪 and deprotonated N_未1 sites. As the pH increases to 11鈥?4, both of the N_未1 and N_蔚2 sites could be deprotonated as acceptors to be bound to either Zn(II) or water. All of these findings give a comprehensive set of benchmark values for NMR parameters and structural geometries in variable histidine鈥揨n(II) binding complexes over a wide pH range and might provide insights into the structure鈥損roperty relationship of histidine鈥搈etal complexes in biological metalloproteins.