Paramagnetic NMR studies of blue and purple copper proteins

Molecular Analysis of the Copper-Transporting Efflux System CusCFBA of Escherichia coli

“…Other proteins with a similar color have a binuclear copper center, composed of two copper atoms connected by the sulfhydryl groups of two cysteines. Each of these coppers is also connected to a histidine residue (7,26,32). Recently, another purple periplasmic copper-binding protein has been described (28).…”

Novel 13C direct detection experiments, including extension to the third dimension, to perform the complete assignment of proteins

“…Experiments that rely on heteronuclei, in particular on 13 C, were recently applied to several paramagnetic proteins, where the contribution to line broadening from the paramagnetic center is so large that 1 H signals are broadened beyond detectable limits in a wide sphere around the metal ion [10][11][12][13][14]. These applications promoted the revival of heteronuclear NMR as a means to overcome the limitations imposed to 1 H NMR by fast proton transverse relaxation [15][16][17].…”

A suite of amino acid residue type classification pulse sequences for 13C-detected NMR of proteins

“…Initially developed for proteins that contain paramagnetic centers [4][5][6][7][8][9], where direct detection of 13 C helps to reduce relaxation losses, it has many other advantages, that can overcome the inconvenience of the lower sensitivity of the experiments when compared with 1 H-detected NMR spectroscopy. So, 13 C chemical shifts have a much larger dispersion than 1 H chemical shifts, even in the absence of a stable 3D structure, what makes 13 C-detected NMR very useful in the study of completely or partially unfolded proteins [10][11][12][13][14][15][16][17].…”