Water and bromide in the active center of vanadate-dependent haloperoxidases.
Two aqua-oxovanadium complexes, viz. [A-VO(H2O)(sal-L-Leu)] (1) and [VO(H2O)2(5-Br-sal-Gly)] x H2O(2 x H2O), containing the water ligands in cis- and trans-positions to the oxo group at V-OH2 distances ranging from 2.008 to 2.228 A, have been structurally characterized in order to model the apical electron density feature found in the structures of fungal and algal vanadate-dependent peroxidases. Br K-edge XAS of bromide-treated bromoperoxidase from Ascophyllum nodosum and model compounds (including 2 x H2O) has been used to show that the substrate bromide does not bind to active site vanadium but to a light atom, possibly carbon, in its vicinity.
Rehder
D
D
Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Germany. rehder@xray.chemie.uni-hamburg.de
Schulzke
C
C
Dau
H
H
Meinke
C
C
Hanss
J
J
Epple
M
M
D001665:Binding Sites; D005658:Fungi / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D015394:Molecular Structure; D010544:Peroxidases / Q000737:chemistry*; D000459:Phaeophyceae / Q000201:enzymology; D013052:Spectrometry, X-Ray Emission; D017968:Vanadium Compounds / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D017968:Vanadium Compounds; D014867:Water; D010544:Peroxidases; C026195:bromide peroxidase