- Tytuł:
- Mössbauer Studies of Cu(II) Ions Interaction with the Non-Heme Iron and Cytochrome b$\text{}_{559}$ in a Chlamydomonas reinhardtii PSI Minus Mutant
- Autorzy:
-
Burda, K.
Kruk, J.
Strzałka, K.
Stanek, J.
Schmid, G. H.
Kruse, O. - Tematy:
-
82.39.Jn
82.39.Rt
82.50.Nd
87.15.He
87.64.Pj
89.60.Fe - Pokaż więcej
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Powiązania:
- https://bibliotekanauki.pl/articles/2044646.pdf Link otwiera się w nowym oknie
- Opis:
- Mössbauer spectroscopy was applied, for the first time, to study the interaction of copper ions with the non-heme iron and the heme iron of cytochrome b$\text{}_{559}$ in photosystem II thylakoids isolated from a Chlamydomonas reinhardtii photosystem I minus mutant. We showed that copper ions oxidize the heme iron and change its low spin state into a high spin state. This is probably due to deprotonation of the histidine coordinating the heme. We also found that copper preserves the non-heme iron in a low spin ferrous state, enhancing the covalence of iron bonds as compared to the untreated sample. We suggest that a disruption of hydrogen bonds stabilizing the quinone-iron complex by Cu$\text{}^{2+}$ is the mechanism responsible for a new arrangement of the binding site of the non-heme iron leading to its more "tense" structure. Such a diamagnetic state of the non-heme iron induced by copper results in a magnetic decoupling of iron from the primary quinone acceptor. These results indicate that Cu does not cause removal of the non-heme iron from its binding site. The observed Cu$\text{}^{2+}$ action on the non-heme iron and cytochrome b$\text{}_{559}$ is similar to that previously observed forα-tocopherol quinone.
- Dostawca treści:
- Biblioteka Nauki
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