Exposure of ultraviolet-B (280-320 nm, 1.9 mW m-2 s-1) radiation of intact Spirulina platensis for 9 h caused specific loss of the 85.5 KDa anchor protein of phycobilisomes, the major light-harvesting antenna complex of photosystem II. Associated with the loss of 85.5 KDa protein, the UV-B irradiation also caused photobleaching of phycobilins and alteration in the chromophore protein interactions, as evidenced from the visible circular dichroic measurements, and it also affected the energy transfer process within the phycobilisomes, as inferred from the low-temperature, 77 K, fluorescence spectral analysis. Our results, thus, clearly demonstrate for the first time that the phycobilisomes effectively act as targets for UV-B induced damage of photosynthetic apparatus in cyanobacteria.
|Number of pages||6|
|Journal||Biochemical and biophysical research communications|
|Publication status||Published - Aug 10 1998|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology