Low temperature 65Cu NMR spectroscopy of the Cu+ site in azurin.
(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.
Lipton
Andrew S
AS
Biological Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, Washington 99352, USA.
Heck
Robert W
RW
de Jong
Wibe A
WA
Gao
Amy R
AR
Wu
Xiongjian
X
Roehrich
Adrienne
A
Harbison
Gerard S
GS
Ellis
Paul D
PD
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
D007554:Isotopes; D001400:Azurin; D003300:Copper