title: Low temperature 65Cu NMR spectroscopy of the Cu+ site in azurin.
abstract: (65)Cu central-transition NMR spectroscopy of the blue copper protein azurin in the reduced Cu(I) state, conducted at 18.8 T and 10 K, gave a strongly second order quadrupole perturbed spectrum, which yielded a (65)Cu quadrupole coupling constant of +/-71.2 +/- 1 MHz, corresponding to an electric field gradient of +/-1.49 atomic units at the copper site, and an asymmetry parameter of approximately 0.2. Quantum chemical calculations employing second order Møller-Plesset perturbation theory and large basis sets successfully reproduced these experimental results. Sensitivity and relaxation times were quite favorable, suggesting that NMR may be a useful probe of the electronic state of copper sites in proteins.
authors.affiliation: Biological Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, USA.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Lipton
authors.forename: Robert W
authors.initials: RW
authors.lastname: Heck
authors.forename: Wibe A
authors.initials: WA
authors.lastname: de Jong
authors.forename: Amy R
authors.initials: AR
authors.lastname: Gao
authors.forename: Xiongjian
authors.initials: X
authors.lastname: Wu
authors.forename: Adrienne
authors.initials: A
authors.lastname: Roehrich
authors.forename: Gerard S
authors.initials: GS
authors.lastname: Harbison
authors.forename: Paul D
authors.initials: PD
authors.lastname: Ellis
mesh_terms: D001400:Azurin / Q000737:chemistry*; D020134:Catalytic Domain; D003080:Cold Temperature; D003300:Copper / Q000737:chemistry*; D007554:Isotopes / Q000737:chemistry; D008956:Models, Chemical; D019906:Nuclear Magnetic Resonance, Biomolecular; D011789:Quantum Theory
chemical_list: D007554:Isotopes; D001400:Azurin; D003300:Copper