Metalloproteins constitute an important class of proteins and the characterisation of these complexes is a highly desirable goal for the bioinorganic chemist. Although proteins containing diamagnetic metal ions can in principle be studied by NMR like any non-metal containing protein, paramagnetic proteins represent a greater challenge.

In their Dalton Transactions Perspective, Ivano Bertini and colleagues, from the University of Florence, Italy, present the recent advances in paramagnetic NMR as a tool for the characterisation of protein structure and dynamics.

The authors focus on the importance of ¹³C direct-detection NMR for the assignment of paramagnetic systems both in solution and solid state. They also discuss how these advances allow the study of different domains of a single protein and protein-protein interactions.