High‐specific binding of Fe(II) at the Mn‐binding site in Mn‐depleted PSII membranes from spinach

FEBS Letters

Semin, B.K.²  Rubin, A.B.²  Ivanov, I.I.²  Parak, F.¹ 

[1] Fakultät für Physik, E17, Technische Universität München 85748 Garching, Germany;Biophysics Department, Biological Faculty, Moscow State University, Moscow, 119899, Russian Federation

关键词: Photosynthesis;    Photosystem II;    Oxygen evolving complex;    Manganese;    Iron;   

DOI  :  10.1016/0014-5793(95)01215-Z

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The interaction of Fe(II) and Fe(III) with the ‘high-affinity Mn-binding site’ in Mn-depleted photosystem II (PSII) was investigated using diphenilcarbazide (DPC)/2, 6-dichlorophenol-indophenol (DCIP) inhibition assay. Fe(III) was ineffective in the inhibition of DPC-DCIP reaction while Fe(II) decreased the rate of DCIP photoreduction supported by DPC in the same concentration range as Mn(II). The effectivity of the interaction of Fe(II) with the high affinity Mn-binding site depends on different anions in the same manner as for Mn(II) and coincides with hierarchy observed for the stimulation of O₂ evolution. The Fe(II) binding is accompanied by its oxidation. By using reductants it was shown that the high affinity site contains a redox-active component and the reduction of this component totally prevents the binding of Fe(II).

【 授权许可】

Unknown