Biochemical characterization of photosystem I complexes having different subunit compositions of fucoxanthin chlorophyll a/c-binding proteins in the diatom Chaetoceros gracilis

Ryo Nagao, Yoshifumi Ueno, Fusamichi Akita, Takehiro Suzuki, Naoshi Dohmae, Seiji Akimoto, Jian-Ren Shen

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Diatoms are dominant phytoplankton in aquatic environments and have unique light-harvesting apparatus, fucoxanthin chlorophyll a/c-binding protein (FCP). Diatom photosystem I (PSI) interacts with specific FCPs (FCPI); however, it remains unclear how PSI cores receive excitation energy from FCPI. To analyze the energy transfer dynamics, it is necessary to isolate both PSI cores and PSI–FCPI complexes. In this study, we prepared three PSI complexes, which are PSI–FCPI membrane fragments, detergent-solubilized PSI–FCPI supercomplexes and PSI core-like complexes, from the marine centric diatom, Chaetoceros gracilis, and examined their biochemical properties. Both the PSI–FCPI membrane fragments and supercomplexes showed similar subunit compositions including FCPI, whereas the PSI complexes were devoid of most FCPI subunits. The purity and homogeneity of the two detergent-solubilized PSI preparations were verified by clear-native PAGE and electron microscopy. The difference of pigment contents among the three PSI samples was shown by absorption spectra at 77 K. The intensity in the whole spectrum of PSI–FCPI membranes was much higher than those of the other two complexes, while the spectral shape of PSI complexes was similar to that of cyanobacterial PSI core complexes. 77-K fluorescence spectra of the three PSI preparations exhibited different spectral shapes, especially peak positions and band widths. Based on these observations, we discuss the merits of three PSI preparations for evaluating excitation energy dynamics in diatom PSI–FCPI complexes.

Original languageEnglish
JournalPhotosynthesis Research
DOIs
Publication statusAccepted/In press - Jan 1 2018

Fingerprint

Chaetoceros gracilis
Chlorophyll Binding Proteins
Photosystem I Protein Complex
Diatoms
Bacillariophyceae
photosystem I
chlorophyll
Chemical analysis
Excitation energy
Membranes
detergents
Detergents
chlorophyll binding proteins
Native Polyacrylamide Gel Electrophoresis
Phytoplankton
Energy Transfer
energy
energy transfer
aquatic environment
Pigments

Keywords

  • Chaetoceros gracilis
  • Diatom
  • FCP
  • PSI

ASJC Scopus subject areas

  • Biochemistry
  • Plant Science
  • Cell Biology

Cite this

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title = "Biochemical characterization of photosystem I complexes having different subunit compositions of fucoxanthin chlorophyll a/c-binding proteins in the diatom Chaetoceros gracilis",
abstract = "Diatoms are dominant phytoplankton in aquatic environments and have unique light-harvesting apparatus, fucoxanthin chlorophyll a/c-binding protein (FCP). Diatom photosystem I (PSI) interacts with specific FCPs (FCPI); however, it remains unclear how PSI cores receive excitation energy from FCPI. To analyze the energy transfer dynamics, it is necessary to isolate both PSI cores and PSI–FCPI complexes. In this study, we prepared three PSI complexes, which are PSI–FCPI membrane fragments, detergent-solubilized PSI–FCPI supercomplexes and PSI core-like complexes, from the marine centric diatom, Chaetoceros gracilis, and examined their biochemical properties. Both the PSI–FCPI membrane fragments and supercomplexes showed similar subunit compositions including FCPI, whereas the PSI complexes were devoid of most FCPI subunits. The purity and homogeneity of the two detergent-solubilized PSI preparations were verified by clear-native PAGE and electron microscopy. The difference of pigment contents among the three PSI samples was shown by absorption spectra at 77 K. The intensity in the whole spectrum of PSI–FCPI membranes was much higher than those of the other two complexes, while the spectral shape of PSI complexes was similar to that of cyanobacterial PSI core complexes. 77-K fluorescence spectra of the three PSI preparations exhibited different spectral shapes, especially peak positions and band widths. Based on these observations, we discuss the merits of three PSI preparations for evaluating excitation energy dynamics in diatom PSI–FCPI complexes.",
keywords = "Chaetoceros gracilis, Diatom, FCP, PSI",
author = "Ryo Nagao and Yoshifumi Ueno and Fusamichi Akita and Takehiro Suzuki and Naoshi Dohmae and Seiji Akimoto and Jian-Ren Shen",
year = "2018",
month = "1",
day = "1",
doi = "10.1007/s11120-018-0576-y",
language = "English",
journal = "Photosynthesis Research",
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T1 - Biochemical characterization of photosystem I complexes having different subunit compositions of fucoxanthin chlorophyll a/c-binding proteins in the diatom Chaetoceros gracilis

AU - Nagao, Ryo

AU - Ueno, Yoshifumi

AU - Akita, Fusamichi

AU - Suzuki, Takehiro

AU - Dohmae, Naoshi

AU - Akimoto, Seiji

AU - Shen, Jian-Ren

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Diatoms are dominant phytoplankton in aquatic environments and have unique light-harvesting apparatus, fucoxanthin chlorophyll a/c-binding protein (FCP). Diatom photosystem I (PSI) interacts with specific FCPs (FCPI); however, it remains unclear how PSI cores receive excitation energy from FCPI. To analyze the energy transfer dynamics, it is necessary to isolate both PSI cores and PSI–FCPI complexes. In this study, we prepared three PSI complexes, which are PSI–FCPI membrane fragments, detergent-solubilized PSI–FCPI supercomplexes and PSI core-like complexes, from the marine centric diatom, Chaetoceros gracilis, and examined their biochemical properties. Both the PSI–FCPI membrane fragments and supercomplexes showed similar subunit compositions including FCPI, whereas the PSI complexes were devoid of most FCPI subunits. The purity and homogeneity of the two detergent-solubilized PSI preparations were verified by clear-native PAGE and electron microscopy. The difference of pigment contents among the three PSI samples was shown by absorption spectra at 77 K. The intensity in the whole spectrum of PSI–FCPI membranes was much higher than those of the other two complexes, while the spectral shape of PSI complexes was similar to that of cyanobacterial PSI core complexes. 77-K fluorescence spectra of the three PSI preparations exhibited different spectral shapes, especially peak positions and band widths. Based on these observations, we discuss the merits of three PSI preparations for evaluating excitation energy dynamics in diatom PSI–FCPI complexes.

AB - Diatoms are dominant phytoplankton in aquatic environments and have unique light-harvesting apparatus, fucoxanthin chlorophyll a/c-binding protein (FCP). Diatom photosystem I (PSI) interacts with specific FCPs (FCPI); however, it remains unclear how PSI cores receive excitation energy from FCPI. To analyze the energy transfer dynamics, it is necessary to isolate both PSI cores and PSI–FCPI complexes. In this study, we prepared three PSI complexes, which are PSI–FCPI membrane fragments, detergent-solubilized PSI–FCPI supercomplexes and PSI core-like complexes, from the marine centric diatom, Chaetoceros gracilis, and examined their biochemical properties. Both the PSI–FCPI membrane fragments and supercomplexes showed similar subunit compositions including FCPI, whereas the PSI complexes were devoid of most FCPI subunits. The purity and homogeneity of the two detergent-solubilized PSI preparations were verified by clear-native PAGE and electron microscopy. The difference of pigment contents among the three PSI samples was shown by absorption spectra at 77 K. The intensity in the whole spectrum of PSI–FCPI membranes was much higher than those of the other two complexes, while the spectral shape of PSI complexes was similar to that of cyanobacterial PSI core complexes. 77-K fluorescence spectra of the three PSI preparations exhibited different spectral shapes, especially peak positions and band widths. Based on these observations, we discuss the merits of three PSI preparations for evaluating excitation energy dynamics in diatom PSI–FCPI complexes.

KW - Chaetoceros gracilis

KW - Diatom

KW - FCP

KW - PSI

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