onr:"swepub:oai:lup.lub.lu.se:05cd73e4-4947-4f92-81f3-0d8ae9fa2fa2"
Search: onr:"swepub:oai:lup.lub.lu.se:05cd73e4-4947-4f92-81f3-0d8ae9fa2fa2" > The role of cytochr...
- 1 of 1
- Previous record
- Next record
- To hitlist
- Magnusson, Ann (author)
The role of cytochrome b559 and tyrosineD in protection against photoinhibition during in vivo photoactivation of Photosystem II
- Article/chapterEnglish1999
Publisher, publication year, extent ...
- 1999
Numbers
- LIBRIS-ID:oai:lup.lub.lu.se:05cd73e4-4947-4f92-81f3-0d8ae9fa2fa2
- https://lup.lub.lu.se/record/125358URI
- https://doi.org/10.1016/S0005-2728(99)00044-4DOI
Supplementary language notes
- Language:English
- Summary in:English
Part of subdatabase
- SwePubSwePub
Classification
Notes
- In vivo photoactivation of Photosystem II was studied in the FUD39 mutant strain of the green alga Chlamydomonas reinhardtii which lacks the 23 kDa protein subunit involved in water oxidation. Dark grown cells, devoid of oxygen evolution, were illuminated at 0.8 μE m-2&#;s-1 light intensity which promotes optimal activation of oxygen evolution, or at 17 μE m-2&#;s-1, where photoactivation compete with deleterious photodamage. The involvement of the two redox active cofactors tyrosineD and cytochrome b559 during the photoactivation process, was investigated by EPR spectroscopy. TyrosineD on the D2 reaction center protein functions as auxiliary electron donor to the primary donor P680+ during the first minutes of photoactivation at 0.8 μE m-2&#;s-1 (compare with Rova et al., Biochemistry, 37 (1998) 11039-11045.). Here we show that also cytochrome b559 was rapidly oxidized during the first 10 min of photoactivation with a similar rate to tyrosineD. This implies that both cytochrome b559 and tyrosineD may function as auxiliary electron donors to P680+ and/or the oxidized tyrosine&#;Z on the D1 protein, to avoid photoinhibition before successful photoactivation was accomplished. As the catalytic water-oxidation successively became activated, TyrosineD remained oxidized while cytochrome b559 became rereduced to the equilibrium level that was observed prior to photoactivation. At 17 μE m-2&#;s-1 light intensity, where photoinhibition competes significantly with photoactivation, tyrosineD was very rapidly completely oxidized, after which the amount of oxidized tyrosineD decreased due to photoinhibition. In contrast, cytochrome b559 became reduced during the first 2 min of photoactivation at 17 μE m-2&#;s-1. After this, it was reoxidized, returning to the equilibrium level within 10 min. Thus, during in vivo photoactivation in high-light cytochrome b559 serves two functions. Initially, it probably oxidizes the reduced primary acceptor pheophytin, thereby relieving the acceptor side of reductive pressure, and later on it serves as auxiliary electron donor, preventing donor-side photoinhibition.
Subject headings and genre
- NATURVETENSKAP Biologi hsv//swe
- NATURAL SCIENCES Biological Sciences hsv//eng
Added entries (persons, corporate bodies, meetings, titles ...)
- Rova, Maria (author)
- Mamedov, FikretLund University,Lunds universitet,Biokemi och Strukturbiologi,Centrum för Molekylär Proteinvetenskap,Kemiska institutionen,Institutioner vid LTH,Lunds Tekniska Högskola,Biochemistry and Structural Biology,Center for Molecular Protein Science,Department of Chemistry,Departments at LTH,Faculty of Engineering, LTH(Swepub:lu)biok-fma (author)
- Fredriksson, Per-Olof (author)
- Styring, StenbjörnLund University,Lunds universitet,Biokemi och Strukturbiologi,Centrum för Molekylär Proteinvetenskap,Kemiska institutionen,Institutioner vid LTH,Lunds Tekniska Högskola,Biochemistry and Structural Biology,Center for Molecular Protein Science,Department of Chemistry,Departments at LTH,Faculty of Engineering, LTH(Swepub:lu)biok-sst (author)
- Biokemi och StrukturbiologiCentrum för Molekylär Proteinvetenskap (creator_code:org_t)
Related titles
- In:Biochimica et Biophysica Acta - Bioenergetics1411:1, s. 180-1910005-2728
Internet link
Find in a library
- Biochimica et Biophysica Acta - Bioenergetics (Search for host publication in LIBRIS)
To the university's database
- 1 of 1
- Previous record
- Next record
- To hitlist
Find more in SwePub
- By the author/editor
- Magnusson, Ann
- Rova, Maria
- Mamedov, Fikret
- Fredriksson, Per ...
- Styring, Stenbjö ...
- About the subject
-
- NATURAL SCIENCES
- NATURAL SCIENCES
- and Biological Scien ...
- Articles in the publication
- Biochimica et Bi ...
- By the university
- Lund University
Search outside SwePub
- Extend your search to:
- Google Book Search
- Google Scholar
Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.
- Copyright © LIBRIS - National Library Systems
- LIBRIS.kb.se
