title: Cross correlation rates between Curie spin and dipole-dipole relaxation in paramagnetic proteins: the case of cerium substituted calbindin D9k.
abstract: Cross correlation rates between Curie spin relaxation and H-N dipole-dipole coupling (gamma(HM,HN)CS,DD) have been determined for a calcium binding protein, Calbindin D9k, in which one of the two calcium ions is substituted with cerium(III). Gamma(HM,HN)CS,DD values depend on both the metal-to-proton distances and the M-H-N angles and can be used as an additional constraint in order to refine the solution structure of paramagnetic metalloproteins. For this purpose, we have implemented a new module (CCR-DYANA) in a version of the program DYANA (PARAMAGNETIC-DYANA), which can be used together with other paramagnetism-based constraints such as pseudocontact shifts, residual dipolar couplings and hyperfine based Karplus relationships. This integrated structure calculation protocol has the advantage that different paramagnetic-based constraints are treated by the same algorithm in a way that the efficiency of each class of constraints can be analyzed and compared.
authors.affiliation: Magnetic Resonance Center, University of Florence, Italy. bertini@cerm.unifi.it
authors.forename: Ivano
authors.initials: I
authors.lastname: Bertini
authors.forename: Gabriele
authors.initials: G
authors.lastname: Cavallaro
authors.forename: Marta
authors.initials: M
authors.lastname: Cosenza
authors.forename: Rainer
authors.initials: R
authors.lastname: Kümmerle
authors.forename: Claudio
authors.initials: C
authors.lastname: Luchinat
authors.forename: Mario
authors.initials: M
authors.lastname: Piccioli
authors.forename: Luisa
authors.initials: L
authors.lastname: Poggi
mesh_terms: D000465:Algorithms; D064026:Calbindins; D002563:Cerium / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D006860:Hydrogen Bonding; D019906:Nuclear Magnetic Resonance, Biomolecular; D011487:Protein Conformation; D011522:Protons; D064030:S100 Calcium Binding Protein G / Q000737:chemistry*; D012996:Solutions
chemical_list: D064026:Calbindins; D011522:Protons; D064030:S100 Calcium Binding Protein G; D012996:Solutions; D002563:Cerium