title: Paramagnetic shifts in solid-state NMR of proteins to elicit structural information.
abstract: The recent observation of pseudocontact shifts (pcs) in (13)C high-resolution solid-state NMR of paramagnetic proteins opens the way to their application as structural restraints. Here, by investigating a microcrystalline sample of cobalt(II)-substituted matrix metalloproteinase 12 [CoMMP-12 (159 AA, 17.5 kDa)], it is shown that a combined strategy of protein labeling and dilution of the paramagnetic species (i.e., (13)C-,(15)N-labeled CoMMP-12 diluted in unlabeled ZnMMP-12, and (13)C-,(15)N-labeled ZnMMP-12 diluted in unlabeled CoMMP-12) allows one to easily separate the pcs contributions originated from the protein internal metal (intramolecular pcs) from those due to the metals in neighboring proteins in the crystal lattice (intermolecular pcs) and that both can be used for structural purposes. It is demonstrated that intramolecular pcs are significant structural restraints helpful in increasing both precision and accuracy of the structure, which is a need in solid-state structural biology nowadays. Furthermore, intermolecular pcs provide unique information on positions and orientations of neighboring protein molecules in the solid phase.
authors.affiliation: Magnetic Resonance Center, University of Florence, Via Luigi Sacconi 6, 50019 Sesto Fiorentino, Italy.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Balayssac
authors.forename: Ivano
authors.initials: I
authors.lastname: Bertini
authors.forename: Anusarka
authors.initials: A
authors.lastname: Bhaumik
authors.forename: Moreno
authors.initials: M
authors.lastname: Lelli
authors.forename: Claudio
authors.initials: C
authors.lastname: Luchinat
mesh_terms: D003035:Cobalt; D007553:Isotope Labeling; D008280:Magnetics; D053508:Matrix Metalloproteinase 12 / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular
chemical_list: D003035:Cobalt; D053508:Matrix Metalloproteinase 12