Linked Life Data

11747455

Source:http://linkedlifedata.com/resource/pubmed/id/11747455

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
51
pubmed:dateCreated
2001-12-18
pubmed:abstractText
Distribution of phycobilisomes between photosystem I (PSI) and photosystem II (PSII) complexes in the cyanobacterium Spirulina platensis has been studied by analysis of the action spectra of H2 and O2 photoevolution and by analysis of the 77 K fluorescence excitation and emission spectra of the photosystems. PSI monomers and trimers were spectrally discriminated in the cell by the unique 760 nm low-temperature fluorescence, emitted by the trimers under reductive conditions. The phycobilisome-specific 625 nm peak was observed in the action spectra of both PSI and PSII, as well as in the 77 K fluorescence excitation spectra for chlorophyll emission at 695 nm (PSII), 730 nm (PSI monomers), and 760 nm (PSI trimers). The contributions of phycobilisomes to the absorption, action, and excitation spectra were derived from the in vivo absorption coefficients of phycobiliproteins and of chlorophyll. Analyzing the sum of PSI and PSII action spectra against the absorption spectrum and estimating the P700:P680 reaction center ratio of 5.7 in Spirulina, we calculated that PSII contained only 5% of the total chlorophyll, while PSI carried the greatest part, about 95%. Quantitative analysis of the obtained data showed that about 20% of phycobilisomes in Spirulina cells are bound to PSII, while 60% of phycobilisomes transfer the energy to PSI trimers, and the remaining 20% are associated with PSI monomers. A relevant model of organization of phycobilisomes and chlorophyll pigment-protein complexes in Spirulina is proposed. It is suggested that phycobilisomes are connected with PSII dimers, PSI trimers, and coupled PSI monomers.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15780-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11747455-Bacterial Proteins, pubmed-meshheading:11747455-Chlorophyll, pubmed-meshheading:11747455-Cyanobacteria, pubmed-meshheading:11747455-Dimerization, pubmed-meshheading:11747455-Freezing, pubmed-meshheading:11747455-Light-Harvesting Protein Complexes, pubmed-meshheading:11747455-Oxygen, pubmed-meshheading:11747455-Photolysis, pubmed-meshheading:11747455-Photosynthetic Reaction Center Complex Proteins, pubmed-meshheading:11747455-Photosystem I Protein Complex, pubmed-meshheading:11747455-Photosystem II Protein Complex, pubmed-meshheading:11747455-Phycobilisomes, pubmed-meshheading:11747455-Polarography, pubmed-meshheading:11747455-Proteins, pubmed-meshheading:11747455-Spectrometry, Fluorescence, pubmed-meshheading:11747455-Spectrophotometry, pubmed-meshheading:11747455-Thylakoids
pubmed:year
2001
pubmed:articleTitle
Interaction of phycobilisomes with photosystem II dimers and photosystem I monomers and trimers in the cyanobacterium Spirulina platensis.
pubmed:affiliation
A. N. Bakh Institute of Biochemistry, Russian Academy of Sciences, Moscow 117071, Russia.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't