The relation between the chloride status of the photosynthetic water splitting complex and the inhibitory effectiveness of amines

✍ Scribed by Peter H. Homann

• Book ID: 104627942
• Publisher: Springer
• Year: 1986
• Tongue: English
• Weight: 393 KB
• Volume: 10
• Category: Article
• ISSN: 0166-8595
• DOI: 10.1007/bf00118316

✦ Synopsis

The protective role of chloride ions (Cl-) against inhibition of the photosynthetic water splitting complex by amines was investigated with purified photosystem II membrane particles from tobacco chloroplasts. Seemingly competitive interactions occurred between CI-(except at low concentrations) and Trls, but not between Cl-and NH 3. The rate of CIrelease was not increased by the amines but, instead, may have been limited by a labillzation under the experimental conditions of the extrinsic 23 kDa polypeptide.

An additional detachment of the 18 kDa polypeptide was seen when S042-ions were present.

Tris induced changes of the thermoluminescence patterns of flash illuminated photosystem II particles were found to be different from those caused by either CI-deficiency or high pH. It is concluded that the protective functions of CI-are brought about not because it is bound to the target site of the inhibitory actions of Lewis bases like amines and hydroxyl ions. Instead, this effect of Cl-may be due to its influence on the tertiary and quaternary structures of the water oxidizing protein complex.

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