1. Gas-phase complexes of Ni2+ and Ca2+ with deprotonated histidylhistidine (HisHis): A model case for polyhistidyl-metal binding motifs
- Author
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Giel Berden, Jonathan Martens, Robert C. Dunbar, Katrin Peckelsen, Mathias Schäfer, Anthony J. H. M. Meijer, Jos Oomens, and Molecular Spectroscopy (HIMS, FNWI)
- Subjects
Dipeptide ,Molecular Structure and Dynamics ,Chemistry ,010401 analytical chemistry ,Solvation ,010402 general chemistry ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Dissociation (chemistry) ,0104 chemical sciences ,Metal ,chemistry.chemical_compound ,Crystallography ,Deprotonation ,Main group element ,visual_art ,visual_art.visual_art_medium ,Moiety ,Infrared multiphoton dissociation ,FELIX ,Physical and Theoretical Chemistry ,Spectroscopy - Abstract
In the complex formed between the calcium cation (Ca2+) and a deprotonated HisHis dipeptide, the complex adopts a charge solvation (CS) structure. Ca2+, a weak binding main group metal cation, interacts with the oxygens of the peptide carbonyl moiety and the deprotonated C-terminus. In contrast, the much stronger binding Ni2+ cation deprotonates the peptide nitrogen and induces an iminolate (Im) ligand structure in the [Ni(HisHis-H)]+ complex ion. The combination of infrared multiple-photon dissociation (IRMPD) spectroscopy and quantum chemistry evidence these two representative binding motifs. The iminolate coordination pattern identified and characterized in the [Ni(HisHis-H)]+ complex serves as a model case for nickel complexes of poly-histidyl-domains and is thereby also of interest to better understand the fundamentals of immobilized metal ion affinity chromatography as well as of Ni co-factor chemistry in enzymology.
- Published
- 2017