Metal Ion Coordination Chemistry in Biological Systems

Metal ions are indispensable to life, serving structural, catalytic and regulatory roles in myriad biological processes. Coordination chemistry lies at the heart of these functions, defining how metal centres bind to proteins, peptides and small molecules within cells. The geometry and electronic properties of these complexes govern enzyme activity, electron transfer and signal transduction. Common biological metals such as iron, zinc, copper and manganese adopt a variety of coordination numbers and ligand sets, from four‐coordinate tetrahedral zinc fingers stabilising DNA‐binding domains to six‐coordinate iron centres in oxygen‐transport proteins. The selective binding of metal ions is achieved through a combination of hard and soft donor atoms—typically oxygen, nitrogen and sulfur—arranged in precise protein scaffolds. Such selectivity underpins processes including nutrient uptake, immune defence, oxidative phosphorylation and metal trafficking. Misregulation of metal coordination can lead to disease, as seen in neurodegeneration and metabolic disorders. Advances in crystallography, spectroscopy and computational modelling have illuminated the dynamic interplay between metal centres and their biological environment, revealing mechanisms of metal insertion, exchange and redox cycling. A comprehensive understanding of metal ion coordination chemistry thus offers routes to novel therapeutics, biomaterials and diagnostic tools, while shedding light on fundamental principles of biological organisation.

Research from Nature Portfolio

High‐resolution structural analysis of a metal‐dependent tetramerisation motif has revealed how clustered histidine residues coordinate multiple cobalt ions to stabilise antibody fragments in a defined assembly. The identified motif comprises four short β-strands, each contributing histidine side chains to a central metal cluster, which in turn promotes reversible oligomerisation. Biophysical experiments and molecular dynamics simulations demonstrated that the cobalt‐stabilised interface can be transferred between related protein constructs, suggesting its utility as a modular scaffold for cryo-electron microscopy fiducials or the design of metal‐responsive biomaterials. This work highlights the power of precise metal coordination to control protein assembly and dynamics.

Metal Ion Coordination Chemistry in Biological Systems publication trend

The graph below shows the total number of articles in metal ion coordination chemistry in biological systems across all publications each year (not limited to Nature Index journals).

Technical terms

Coordination sphere: The arrangement of donor atoms directly bonded to a metal ion.

Ligand: A molecule or ion that donates one or more electron pairs to a central metal atom.

Chelation: The simultaneous binding of a single ligand to a metal through multiple donor sites.

Metallophore: A small molecule produced by organisms to bind and transport metal ions.

Redox potential: A measure of the tendency of a chemical species to acquire electrons and be reduced.

References

1. Structure, dynamics and transferability of the metal-dependent polyhistidine tetramerization motif TetrHis for single-chain Fv antibodies. Communications Chemistry (2023).
2. CH vs. HC—Promiscuous Metal Sponges in Antimicrobial Peptides and Metallophores. Molecules (2023).
3. Assay Development for Metal-Dependent EnzymesInfluence of Reaction Buffers on Activities and Kinetic Characteristics. ACS Omega (2023).
4. Intermediate Cu(II)-Thiolate Species in the Reduction of Cu(II)GHK by Glutathione: A Handy Chelate for Biological Cu(II) Reduction. Inorganic Chemistry (2021).