Heat-induced disassembly and degradation of chlorophyll-containing protein complexes in vivo
Jazyk angličtina Země Nizozemsko Médium print-electronic
Typ dokumentu časopisecké články, práce podpořená grantem
PubMed
19712665
DOI
10.1016/j.bbabio.2009.08.001
PII: S0005-2728(09)00247-3
Knihovny.cz E-zdroje
- MeSH
- biologické pigmenty analýza MeSH
- chlorofyl analýza MeSH
- fotosyntéza MeSH
- ječmen (rod) metabolismus MeSH
- listy rostlin chemie metabolismus účinky záření MeSH
- molekulová hmotnost MeSH
- světlo MeSH
- světlosběrné proteinové komplexy chemie metabolismus MeSH
- termodynamika MeSH
- tylakoidy chemie MeSH
- vysoká teplota MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biologické pigmenty MeSH
- chlorofyl MeSH
- světlosběrné proteinové komplexy MeSH
Gradual heating of green leaves up to non-physiological temperatures is often used to estimate thermal stability of photosynthetic apparatus. However, a complete sequence of heat-induced disassembly and denaturation of chlorophyll-containing protein complexes (CPCs) has not been reported yet. In this work, we heated (1 degrees C x min(-1)) barley leaves to temperatures selected according to the changes in the chlorophyll fluorescence temperature curve (FTC) and we analyzed CPC stability by two-dimensional native Deriphat/SDS-PAGE. The first distinct change in both structure and function of photosystem II (PSII) appeared at 40-50 degrees C. PSII core (CCII) dimers began to dissociate monomers, which was accompanied by a decrease in PSII photochemistry and reflected in FTC as the first fluorescence increase. Further changes in CPCs appeared at 57-60 degrees C, when FTC increases to its second maximum. Photosystem I (PSI) cores (CCI) partially dissociated from light-harvesting complexes of PSI (LHCI) and formed aggregates. The rest of CCI-LHCI complexes, as well as the CCI aggregates, degraded to the PSI-A/B heterodimer in leaves heated to 70 degrees C. Heating to these temperatures led to a complete degradation of CCII components and corresponding loss of PSII photochemistry. Trimeric light-harvesting complexes of PSII (LHCII) markedly dissociated to monomers and denatured, as evidenced by a release of large amount of free chlorophylls. Between 70 and 80 degrees C, a complete degradation of LHCII occurred, leaving the PSI-A/B heterodimer as the only detectable CPC in the membrane. This most thermostable CPC disappeared after heating to 90 degrees C, which corresponded to a loss of PSI photochemistry.
Citace poskytuje Crossref.org
