The effect of UVB irradiation on the phycobilisomes (PBSs) of Synechococcus sp. PCC 7942 cells was studied. The sucrose density-gradient-isolated PBSs from in vivo UVB-treated (280-320 nm) cells showed a strong decrease in β-phycocyanin (βPC) and α-phycocyanin (αPC) polypeptides, in addition to a decrease in the linker polypeptides LCM 75 (linker connecting the core to the thylakoid membranes), LR 33 (linker in the rod structure), LRC 31.5 (linker connecting the rod to the core) and LRC 29. In vitro UVB treatment of gradient-isolated intact PBSs for 1 h had no effect on any of the constituent polypeptides, and only after 2 h was a degradation of LCM 75 and LR 33 and a decrease in PPC evident. Further investigation of phycobiliproteins (4 h of UVB irradiation) using polyclonal antibody directed against purified whole PBSs revealed that, in vivo, there was a gradual decline in the levels of LCM 75, LR 33, LRC 31.5, LRC 29, βPC and αPC.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Photochemistry and Photobiology B: Biology|
|State||Published - Oct 1997|
ASJC Scopus subject areas
- Radiological and Ultrasound Technology
- Radiology Nuclear Medicine and imaging