Hyperfine shifted water resonances

NMR spectra have been reported for the Rieske-type ferredoxins from Xanthobacter strain Py2 (88) and of toluene 4-monooxygenase from Pseudomonas mendocina (T4MOC) (88a) as well as for the water-soluble Rieske fragment from the bci complex of Paracoccus deni-trificans (ISFpd) (89). The spectra of these proteins are similar, which is consistent with the close structural relationship between the three proteins. In the reduced (paramagnetic) state, all three proteins show several hyperfine-shifted resonances between +83 and -16 ppm at 400 MHz or between 110 and +25 ppm at 300 MHz (Table X). 

Addition of F or a protic solvent (water, alcohol) causes an upfield shift of the resonance accompanied by line broadening with concommitant loss the silicon-fluorine hyperfine structure. 

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