Premium
Reconstitution of Photosystem II Reaction Center with Cu‐Chlorophyll a
Author(s) -
Liu Shuang,
Dong FengQin,
Yang ChunHong,
Tang ChongQin,
Kuang TingYun
Publication year - 2006
Publication title -
journal of integrative plant biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.734
H-Index - 83
eISSN - 1744-7909
pISSN - 1672-9072
DOI - 10.1111/j.1744-7909.2006.00352.x
Subject(s) - photosystem ii , photosynthetic reaction centre , light harvesting complexes of green plants , center (category theory) , chlorophyll a , chlorophyll , chemistry , photosynthesis , photosystem i , photochemistry , botany , biology , crystallography
An isolated photosystem (PS) II reaction center (RC) with altered pigment content was obtained by chemical exchange of native chlorophyll a (Chl) with externally added Cu‐Chl a (Cu‐Chl). Pigment composition and spectroscopic properties of the RC exchanged with Cu‐Chl were compared with native RC and RC treated with Chl in the same way. High‐performance liquid chromatography analysis showed approximately 0.5 Cu‐Chl per two pheophytin in the Cu‐Chl‐reconstituted RC preparation. Insertion of Cu‐Chl resulted in a decrease in absorption at 670 nm and an increase at 660 nm, suggesting that the peripheral Chl may have been displaced. Fluorescence emission spectra of the Cu‐Chl‐reconstituted RC displayed a marked decrease in fluorescence yield and a blue shift of the band maximum, accompanied by the appearance of a broad peak at a shorter wavelength, indicating that energy transfer in the modified RC was disturbed by Cu‐Chl, a quencher of the excited state. However, there were few differences in the circular dichroism (CD) spectra, suggesting that the arrangement of pigments and proteins responsible for the CD signal was not significantly affected. In addition, no obvious change in peptide components was found after the exchange procedure. (Managing editor: Ping He)