(Model) studies on vanadate‐dependent bromo/iodoperoxidase from Ascophyllum nodosum VO2+ is not incorporated into the active site

FEBS Letters

Knüttel, Karlheinz¹  Vilter, Hans²  Müller, Achim¹  Rehder, Dieter²  Wittneben, Volker¹ 

[1] Faculty of Inorganic Chemistry, University of Bielefeld, W-4800 Bielefeld, Germany;Institute of Inorganic and Applied Chemistry, University of Hamburg, W-2000 Hamburg 13, Germany

关键词: Vanadate-dependent peroxidase;    Vanadyl—peptide complex;    Vanadate—peptide complex;    Electron paramagnetic resonance;    51V Nuclear magnetic resonance spectroscopy;   

DOI  :  10.1016/0014-5793(92)80272-I

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Vanadate-dependent peroxidase A.n.I. the main isoenzyme (M _r = 100 kDa) from the seaweed. Ascophyllum nodosum, contains 2 V per enzyme molecule (as shown by ICP-MS metal analysis) after complete reconstitution with vanadate (V), possibly distributed in a 1:1 ratio between the surface and active site. VO²⁺ is only weakly associated to the surface of A,n.I. There is no transport channel for VO²⁺. The EPR spectrum of the reduced holoenzyme is unisotropic (axial) already at room temperature, with EPR parameters similar to those of VO²⁺ complexes of small model peptides such as Ala-His, Gly-Tyr, Gly-Ser, Gly-Glu, Ser-Gly and Phe-Glu. The complex formation between Ala-His and H₂VO⁻ ₄ in water has also been investigated (by ⁵¹V NMR); the formation constant at pH 7.2 amounts to 266(28) M⁻¹.

【 授权许可】

Unknown