Relationship between the architecture of zinc coordination and zinc binding affinity in proteins – insights into zinc regulation

Zinc proteins are an integral component of the proteome of all domains of life. Zn(II), one of the most widespread transition elements, serves multiple functions in proteins, such as a catalytic co-factor, a structural center and a signaling component. The mechanism by which proteins associate with and dissociate from Zn(II) and the factors that modulate their affinity and stability remain incompletely understood. In this article, we aim to address how zinc binding sites present in proteins differ in their architecture and how their structural arrangement is associated with protein function, thermodynamic and kinetic stability, reactivity, as well as zinc-dependent regulation. Here, we emphasize that the concentration-dependent functionality of the interprotein zinc binding site may serve as another factor regulating the relationship between cellular Zn(II) availability and protein function.