Preliminary Study On Unknown Proteins And Bilin Chromoproteins Of Synechocystis Sp. Pcc6803

Genome sequencing in Synechocystis sp. PCC6803has been completed. Great progress has been made in the study of gene function, but there are still many genes of unknown function. In order to study these genes, we have got⊿sll0272,⊿sll0524,⊿sll0584,⊿sll0781,⊿sll0939,⊿slr1614,⊿slr1618,⊿slr1674⊿slr1702and⊿slr0280. In this paper, We focus on the physiology(growth under different culture conditions). The results show that: The growth of⊿sll0272was affected by Na+and K+concentrations in the environment. Especially at low salt conditions, it was affected by Na+/K+and grew faster under the higer ratio. And we found the carbohydrate metabolism of Synechocystis sp. PCC6803was significantly affected when its slr0280was deleted. The growth rates of other8mutants have no significant differences compared those of WT.OprB is a porin which selectively transport carbohydrate. Synechocystis sp. PCC6803contain six porins homologous to OprB. They are encoded by sll0772, slU271, slll550, slr0042, slrl841, slrl908, and may be responsible for the selective transport of carbohydrate. In this paper, we have got the⊿sll0772,⊿sll1271and⊿sll1550by replacing sll0772, sll1271and sll1550with Kanamycin resistance gene. We focus on the physiology of these mutants and found there were no significant differences between WT and mutants growth under BG11media short of various components (C, N, P) or BG11media with various carbon sources (glucose, sucrose, sodium pyruvate, sodium citrate).Photodynamic therapy is a new method to treat cancer. Under light irradiation, phycobiliproteins and phytochromes in cyanobacteria may produce phototoxicity, which make them become potential drugs for photodynamic therapy. In this paper, we detected23phycobiliproteins and phytochromes about their phototoxic activity and found the phototoxic activity of PecB-CpcT-PCB was the best, its fatality rate was about22%. But the phototoxic activity do not reach our desired goal and we need to continue screening to get one or more of high phototoxicity.