title: Disintegration of phycobilisomes in a rice field cyanobacterium Nostoc sp. following UV irradiation.
abstract: The effects of ultraviolet-B (UV-B, 280-315 nm) irradiation on survival, growth and phycobilisome assembly have been studied in the N2-fixing cyanobacterium Nostoc sp. Survival and growth were virtually arrested after 120 min of UV irradiation. The phycobiliprotein fractions showed a decrease in absorption and fluorescence as well as a shift towards shorter wavelengths indicating the impairment of energy transfer from phycobiliproteins to the photosynthetic reaction centers. This was further supported by SDS-PAGE analysis of the fractions which revealed a loss in high molecular mass rod-core and core-membrane linker polypeptides. Also the low molecular mass phycobilin (alpha beta) monomers decreased, showing that the supra-molecular organization of the phycobilisomes disintegrated during UV irradiation.
authors.affiliation: Institut für Botanik und Pharmazeutische Biologie, Friedrich-Alexander Universität, Erlangen, Fed. Rep. Germany.
authors.forename: R P
authors.initials: RP
authors.lastname: Sinha
authors.forename: M
authors.initials: M
authors.lastname: Lebert
authors.forename: A
authors.initials: A
authors.lastname: Kumar
authors.forename: H D
authors.initials: HD
authors.lastname: Kumar
authors.forename: D P
authors.initials: DP
authors.lastname: Häder
mesh_terms: D001426:Bacterial Proteins / Q000528:radiation effects*; D000458:Cyanobacteria / Q000254:growth & development / Q000378:metabolism / Q000528:radiation effects*; D045342:Light-Harvesting Protein Complexes; D045524:Phycobilisomes; D010940:Plant Proteins / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D045342:Light-Harvesting Protein Complexes; D045524:Phycobilisomes; D010940:Plant Proteins