Spectroscopic studies of phycobilisome subcore preparations lacking key core chromophores

Assignment of excited state energies to the Lcm, β18 and αAP-B chromophores

Yvonne Gindt, Jianhui Zhou, Donald A. Bryant, Kenneth Sauer

Research output: Contribution to journalArticleResearchpeer-review

47 Citations (Scopus)

Abstract

Chromophore absorption and emission characteristics of the αAP-B, β18 and Lcm (large core-membrane linker) chromopeptides within the phycobilisome core are investigated using genetically engineered strains of Synechococcus sp. PCC 7002. Steady-state and time-resolved emission were used to examine energy transfer in subcore preparations from the wild-type organism and two mutants. Low-temperature (77 K) emission spectra were also measured for intact phycobilisomes from the wild-type and five mutant strains. Mutants retaining either the αAP-B subunit or the unaltered Lcm chromophore resulted in only small changes in the low-temperature emission spectra, while retention of only the β18 subunit resulted in blue-shifted emission spectra. The Lcm chromophore has a room-temperature absorption maximum at 675 nm. In phycobilisomes at 77 K the αAP-B and Lcm chromophores emit at 682-683 nm, and they are the best candidates for long-wavelength emitters also at room temperature. Overlap of these emission spectra with the absorption of chlorophyll a in the associated thylakoid membrane plays a significant role in excitation transfer from the antenna complexes in cyanobacteria.

Original languageEnglish
Pages (from-to)153-162
Number of pages10
JournalBBA - Bioenergetics
Volume1186
Issue number3
DOIs
StatePublished - 29 Jul 1994

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Phycobilisomes
Chromophores
Excited states
Membranes
Temperature
Synechococcus
Thylakoids
Energy Transfer
Cyanobacteria
Energy transfer
Antennas
Wavelength

Keywords

  • Cyanobacterium
  • Energy transfer
  • Fluorescence relaxation
  • Phycobilisome
  • Subcore particle, 18 S

Cite this

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title = "Spectroscopic studies of phycobilisome subcore preparations lacking key core chromophores: Assignment of excited state energies to the Lcm, β18 and αAP-B chromophores",
abstract = "Chromophore absorption and emission characteristics of the αAP-B, β18 and Lcm (large core-membrane linker) chromopeptides within the phycobilisome core are investigated using genetically engineered strains of Synechococcus sp. PCC 7002. Steady-state and time-resolved emission were used to examine energy transfer in subcore preparations from the wild-type organism and two mutants. Low-temperature (77 K) emission spectra were also measured for intact phycobilisomes from the wild-type and five mutant strains. Mutants retaining either the αAP-B subunit or the unaltered Lcm chromophore resulted in only small changes in the low-temperature emission spectra, while retention of only the β18 subunit resulted in blue-shifted emission spectra. The Lcm chromophore has a room-temperature absorption maximum at 675 nm. In phycobilisomes at 77 K the αAP-B and Lcm chromophores emit at 682-683 nm, and they are the best candidates for long-wavelength emitters also at room temperature. Overlap of these emission spectra with the absorption of chlorophyll a in the associated thylakoid membrane plays a significant role in excitation transfer from the antenna complexes in cyanobacteria.",
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author = "Yvonne Gindt and Jianhui Zhou and Bryant, {Donald A.} and Kenneth Sauer",
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Spectroscopic studies of phycobilisome subcore preparations lacking key core chromophores : Assignment of excited state energies to the Lcm, β18 and αAP-B chromophores. / Gindt, Yvonne; Zhou, Jianhui; Bryant, Donald A.; Sauer, Kenneth.

In: BBA - Bioenergetics, Vol. 1186, No. 3, 29.07.1994, p. 153-162.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Spectroscopic studies of phycobilisome subcore preparations lacking key core chromophores

T2 - Assignment of excited state energies to the Lcm, β18 and αAP-B chromophores

AU - Gindt, Yvonne

AU - Zhou, Jianhui

AU - Bryant, Donald A.

AU - Sauer, Kenneth

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