Metal centers in biomolecular solid-state NMR

• Published in: Journal of structural biology Vol. 206; no. 1; pp. 99 - 109
• Main Authors: Malanho Silva, José, Cerofolini, Linda, Giuntini, Stefano, Calderone, Vito, Geraldes, Carlos F.G.C., Macedo, Anjos L., Parigi, Giacomo, Fragai, Marco, Ravera, Enrico, Luchinat, Claudio
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2019
• Subjects: Biosolids; Electronic structure; Paramagnetic NMR; Resolution; Sensitivity; Electronic structure; Sensitivity; Paramagnetic NMR; Biosolids; Resolution
• ISSN: 1047-8477; 1095-8657
• DOI: 10.1016/j.jsb.2018.11.013

[Display omitted] •The electronic structure of paramagnetic centers has a strong impact on the solid-state NMR spectra of the biomolecules to which they are bound.•Slowly relaxing electron spins are usually associated to fast relaxation of the nuclear resonances and to small shifts, therefore are most useful for obtaining distance restraints in the form of paramagnetic relaxation enhancements.•Fast relaxing electron spins usually feature an anisotropic magnetic susceptibility that is reflected in large pseudocontact shifts, which in turn can be used to achieve unambiguous structural information.•Large pseudocontact shifts can yield sizeable intermolecular contributions in crystals, and may contain sufficient information to fully reconstruct the supramolecular arrangement of protein crystals.•Contact shifts are strongly dependent on the reciprocal arrangement of the nuclei with respect to the metal center. Different conformations observed in a crystal could be reflected in largely different contact shift values. Solid state NMR (SSNMR) has earned a substantial success in the characterization of paramagnetic systems over the last decades. Nowadays, the resolution and sensitivity of solid state NMR in biological molecules has improved significantly and these advancements can be translated into the study of paramagnetic biomolecules. However, the electronic properties of different metal centers affect the quality of their SSNMR spectra differently, and not all systems turn out to be equally easy to approach by this technique. In this review we will try to give an overview of the properties of different paramagnetic centers and how they can be used to increase the chances of experimental success.