Application of NMRD to hydration of rubredoxin and a variant containing a (Cys-S)3FeIII(OH) site.

ABSTRACT: Hydration of oxidized rubredoxin (Fe(III)(S-Cys)(4) center) was investigated by (1)H and (17)O relaxation measurements of bulk water as a function of the applied magnetic field (nuclear magnetic relaxation dispersion). Oxidized rubredoxin showed an increased water (1)H relaxation profile with respect to the diamagnetic gallium derivative or reduced species. Analysis of the data shows evidence of exchangeable proton(s) approximately 4.0-4.5 A from the metal ion, the exchange time being longer than 10(-10) s and shorter than 10(-5) s. The correlation time for the proton-electrons interaction is 7 x 10(-11) s and is attributed to the effective electron relaxation time. Its magnitude is consistent with the large signal linewidths of the protein donor nuclei, observed in high resolution NMR spe

SUBMITTER: Bertini I 

PROVIDER: S-EPMC1302634 | biostudies-literature | 2003 Jan

REPOSITORIES: biostudies-literature