Linked Life Data

18371294

Source:http://linkedlifedata.com/resource/pubmed/id/18371294

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2008-5-5
pubmed:abstractText
The mechanism of photodegradation of antenna system in cyanobacteria was investigated using spin trapping ESR spectroscopy, SDS-PAGE and HPLC-MS. Exposure of isolated intact phycobilisomes to illumination with strong white light (3500 micromol m(-2) s(-1) photosynthetically active radiation) gave rise to the formation of free radicals, which subsequently led to specific protein degradation as a consequence of reactive oxygen species-induced cleavage of the polypeptide backbone. The use of specific scavengers demonstrated an initial formation of both singlet oxygen (1O2) and superoxide (O2(-)), most likely after direct reaction of molecular oxygen with the triplet state of phycobiliproteins, generated from intersystem crossing of the excited singlet state. In a second phase carbon-based radicals, detected through the appearance of DMPO-R adducts, were produced either via O2(-) or by direct 1O2 attack on amino acid moieties. Thus photo-induced degradation of intact phycobilisomes in cyanobacteria occurs through a complex process with two independent routes leading to protein damage: one involving superoxide and the other singlet oxygen. This is in contrast to the mechanism found in plants, where damage to the light-harvesting complex proteins has been shown to be mediated entirely by 1O2 generation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:volume
1777
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
417-24
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Generation of reactive oxygen species upon strong visible light irradiation of isolated phycobilisomes from Synechocystis PCC 6803.
pubmed:affiliation
Department of Environmental Sciences, University of Tuscia, Viterbo, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't