pH dependence of the S2 → S3 transition associated with O2 evolution in inside‐out thylakoids

FEBS Letters

Nhu Hung, Suong Phung¹  Delrieu, Marie-José¹  de Kouchkovsky, Françoise¹ 

[1] Laboratoire de Photosynthèse, Centre National de la Recherche Scientifique, BP 1, 91190 Gif-sur-Yvette, France

关键词: pH effect;    Oxygen evolution;    Photosystem II;    Inside-out thylakoid;    Secondary donor;    PS;    photosystem;    DCBQ;    2;    5-dichloro-p-benzoquinone;   

DOI  :  10.1016/0014-5793(85)81268-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In inside-out vesicles, a large difference is observed in oxygen yield activity between pH 6.5 and 7.6 which is in contrast to right-side-out vesicles. The light saturation behaviour of the transition S₂ → S₃ also shows a pH dependence. In inside-out thylakoids, at pH 6.5, the light saturation curve of the S₂ → S₃ transitions exhibits 2 different light saturation processes whereas at pH 7.6 it resembles the light saturation behaviour of the other S-state transitions. This result is explained by the existence of a second donor in the S₂ state (different from the main donor), which contributes to about 30% of the S₂ → S₃ transitions at pH 6.5. This second donor needs to be protonated and thus, is not active at pH 7.6 in inside-out thylakoids.

【 授权许可】

Unknown