Iron components in PS II particles of spinach by Mössbauer spectroscopy
Abstract:
Mössbauer spectrum measured for the iron components of photosystem II (PS II) particles of spinach is a superposition of 4 doublets. Quadrupole splitting and chemical shifting of doublets I-IV are characteristics of proteins with oxidized cytochrome b-559, reduced cytochrome b-559, Fe(3+)-Q complex and Fe(2+) -Q complex respectively. After the PS II particles are treated with La(3+), two doublets of Fe(2+) disappear and Fe(2+) is converted into Fe(3+), indicating that the reduced cytochrome b-559 has been converted into the oxidized cytochrome b-559, and Fe(2+) -Q complex into Fe(3+) -Q complex. The Mössbauer spectrum of PS II particles treated with La(3+) and Ca(2+) shows that Ca(2+) can weaken the inhibitory effect of La(3+) in part, and a portion of the reduced cytochrome b-559 and Fe-Q complex still exist.
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