On the role of the QB protein of PS II in photoinhibition

FEBS Letters

Arntz, B.¹  Trebst, A.¹ 

[1] Lehrstuhl für Biochemie der Pflanzen, Ruhr-Universität Bochum, Postfach 10 21 48, D-4630 Bochum 1, FRG

关键词: Photoinhibition Photosystem II Atrazine QBprotein Thylakoid peptide;   

DOI  :  10.1016/0014-5793(86)80048-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Preillumination of spinach thylakoid membranes under strictly anaerobic conditions (i.e. in the presence of glucose oxidase) and in the absence of an electron acceptor inactivates specifically photosystem (PS) II. Inhibition can be complete within 3 min depending on the glucose oxidase concentration and light intensity. Artificial donor or acceptor systems do not restore PS II. Atrazine binding affinity is not diminished. No degradation of peptide subunits is observed. Trypsinized PS II preparations, in which the Q_B-binding site has been destroyed, can also be inactivated by light. It is concluded that photoinhibition of thylakoid membranes under anaerobic conditions inactivates the reaction center of PS II. This photoinactivation does not depend on the degradation of a peptide subunit. Not only the Q_B site but also a modified (trypsinized) Q_A site can induce photoinhibition.

【 授权许可】

Unknown