TY - JOUR
T1 - Isolation and characterization of oxygen-evolving thylakoid membranes and Photosystem II particles from a marine diatom Chaetoceros gracilis
AU - Nagao, Ryo
AU - Ishii, Akiko
AU - Tada, Osamu
AU - Suzuki, Takehiro
AU - Dohmae, Naoshi
AU - Okumura, Akinori
AU - Iwai, Masako
AU - Takahashi, Takeshi
AU - Kashino, Yasuhiro
AU - Enami, Isao
PY - 2007/12/1
Y1 - 2007/12/1
N2 - Thylakoid membranes retaining high oxygen-evolving activity (about 250 μmol O2/mg Chl/h) were prepared from a marine centric diatom, Chaetoceros gracilis, after disruption of the cells by freeze-thawing. We also succeeded in purification of Photosystem II (PSII) particles by differential centrifugation of the thylakoid membranes after treatment with 1% Triton X-100. The diatom PSII particles showed an oxygen-evolving activity of 850 and 1045 μmol O2/mg Chl/h in the absence and presence of CaCl2, respectively. The PSII particles contained fucoxanthin chlorophyll a/c-binding proteins in addition to main intrinsic proteins of CP47, CP43, D2, D1, cytochrome b559, and the antenna size was estimated to be 229 Chl a per 2 molecules of pheophytin. Five extrinsic proteins were stoichiometrically released from the diatom PSII particles by alkaline Tris-treatment. Among these five extrinsic proteins, four proteins were red algal-type extrinsic proteins, namely, PsbO, PsbQ', PsbV and PsbU, whereas the other one was a novel, hypothetical protein. This is the first report on isolation and characterization of diatom PSII particles that are highly active in oxygen evolution and retain the full set of extrinsic proteins including an unknown protein.
AB - Thylakoid membranes retaining high oxygen-evolving activity (about 250 μmol O2/mg Chl/h) were prepared from a marine centric diatom, Chaetoceros gracilis, after disruption of the cells by freeze-thawing. We also succeeded in purification of Photosystem II (PSII) particles by differential centrifugation of the thylakoid membranes after treatment with 1% Triton X-100. The diatom PSII particles showed an oxygen-evolving activity of 850 and 1045 μmol O2/mg Chl/h in the absence and presence of CaCl2, respectively. The PSII particles contained fucoxanthin chlorophyll a/c-binding proteins in addition to main intrinsic proteins of CP47, CP43, D2, D1, cytochrome b559, and the antenna size was estimated to be 229 Chl a per 2 molecules of pheophytin. Five extrinsic proteins were stoichiometrically released from the diatom PSII particles by alkaline Tris-treatment. Among these five extrinsic proteins, four proteins were red algal-type extrinsic proteins, namely, PsbO, PsbQ', PsbV and PsbU, whereas the other one was a novel, hypothetical protein. This is the first report on isolation and characterization of diatom PSII particles that are highly active in oxygen evolution and retain the full set of extrinsic proteins including an unknown protein.
KW - Chaetoceros gracilis
KW - Diatom
KW - Extrinsic protein
KW - Oxygen evolution
KW - Photosystem II
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U2 - 10.1016/j.bbabio.2007.10.007
DO - 10.1016/j.bbabio.2007.10.007
M3 - Article
C2 - 17996191
AN - SCOPUS:36549034314
VL - 1767
SP - 1353
EP - 1362
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
SN - 0005-2728
IS - 12
ER -