A vanadium‐51 NMR study of the binding of vanadate and peroxovanadate to proteins

51V quadrupolar central transition NMR spectra of buffered (pH 7.6–8.0) solutions of bovine apo‐transferrin (Tf) and bovine prostatic acid phosphatase (Pp) treated with vanadate show normal features (chemical shifts between −515 and −542 ppm) corresponding to the complexation of VO2+ to the Tf binding site and the Pp active centre, respectively. Addition of H2O2 leads to the temporary formation of complexed VO(O2)+(δ ≈ −595). Vanadate‐dependent bromoperoxidase from the alga Ascophyllum nodosum exhibits an unusually high shielding both for the native (δ = −931) and the peroxo form (δ = −1135) of the enzyme. A resonance at −471 ppm is traced back to an inactive form with oxovanadium(V) in a trigonal‐bipyramidal array. Copyright © 2004 John Wiley & Sons, Ltd.