High‐resolution XANES studies on vanadium‐containing haloperoxidase: pH‐dependence and substrate binding

FEBS Letters

Hodgson, Keith O.²  Küsthardt, Ulrich¹  Yilter, Hans³  Hahn, Rainer¹  Hedman, Britt² 

[1] Lehrstuhl für Anorganische Chemie I, TU München, Lichtenbergstr. 4, 85748 Garching, Germany;Stanford Synchroton Radiation Laboratory and Department of Chemistry, Stanford University, Stanford, CA 94305, USA;Gesellschaft für Biotechnologische Forschung GmbH, Mascheroder Weg I, 38124 Braunschweig, Germany

关键词: Vanadium;    Haloperoxidase;    XAS;    XANES;    Ascophyllum nodosum;   

DOI  :  10.1016/0014-5793(93)80180-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

High-resolution X-ray absorption vanadium K-edge spectra were recorded for samples of vanadium-containing bromoperoxidase from the brown alga, Ascophyllum nodosum, at pH 9, 7, 5 and 4, as well as for enzyme samples containing the substrates, hydrogen peroxide and bromide. The well-resolved features of the XANES spectra are discussed. The pH-dependence of the structure of the active site has been studied revealing no significant change of the absorption features. We were able to detect an interaction of H₂O₂ with the vanadium site of the bromoperoxidase using XAS spectroscopy, whereas addition of bromide causes no energy shift of the XANES spectrum. The possible role of vanadium during the enzymatic reaction is discussed on the basis of our results.

【 授权许可】

Unknown