Photodynamic action of phycobiliproteins: in situ generation of reactive oxygen species

He, Jin‐An; Hu, Yi-Zhen; Jiang, Lijin

doi:10.1016/s0005-2728(97)00021-2

Cited by 57 publications

(32 citation statements)

References 19 publications

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“…Under laser irradiation (22), R-PE can absorb and transmit the light to the surrounding oxygen and produce singlet and reactive oxygen species components. These light reaction products can kill cancer cells (23). Antitumor drugs screening by cancer cells has been widely adopted.…”

Section: Discussionmentioning

confidence: 99%

Antitumor function and mechanism of phycoerythrin from Porphyra haitanensis

Pan

Chen

et al. 2013

Biol. Res.

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The anti-tumor eff ect of R-Phycoerythrin (R-PE) from Porphyra haitanensis was studied using cell line HeLa as an in vitro model and Sarcoma-180 (S180) tumor-bearing mice as an in vivo model. The results showed that the combination treatment of R-PE and photodynamic therapy PDT) signifi cantly inhibited the growth of HeLa cells up to 81.5%, with a fair dose-eff ect relationship, but did not inhibit endothelial cells. The annexin v-fi tc/PI fl uorescence staining experiments demonstrated that at doses between 0~60μg/mL, apoptosis cells and later stage apoptosis cells or necrosis cells increased signifi cantly as the R-PE dosage increased. DNA electrophoresis showed that after R-PE+PDT treatment of HeLa cells for 24 hours, a light "smear" band between 100~400bp appeared to indicate the degradation of genomic DNA. The QRT-PCR results showed that R-PE+PDT treatment increased caspase-3 and caspase-10 gene expression and decreased the Bcl-2 gene expression level signifi cantly as the R-PE dose increased, i mplying that R-PE promoted HeLa cell a poptosis. Compared with untreated S180 tumor-bearing mice, R-PE injection signifi cantly inhibited the growth of S180 in tumor-bearing mice up to 41.3% at a dose of 300mg·kg -1 . Simultaneously, the signifi cant increase of superoxide dismutase (SOD) activity in serum (p < 0.01) and the decrease of the malondialdehyde (MDA) level in liver suggests that R-PE improved the anti-oxidant ability of the S180 t umor-bearing mice, which may related to its antitumor eff ect. In addition, the R-PE caused a significant increase (p < 0.05) in the spleen index and thymus index, and a significant increase (p < 0.01) in lymphocyte proliferation, NK cell kill activity and the TNF-α level in the serum of S180 tumor-bearing mice. These results strongly suggest that the antitumor eff ect of R-PE from Porphyra haitanensis functioned by increa sing the immunity and antioxidant ability of S180 tumor-bearing mice, promoting apoptosis by increasing protease gene expression and TNF-α secretion.

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Section: Discussionmentioning

confidence: 99%

Antitumor function and mechanism of phycoerythrin from Porphyra haitanensis

Pan

Chen

et al. 2013

Biol. Res.

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“…The ␤-81/82 PCB chromophores are more exposed in PC and AP of the cpcM mutant strains because of the absence of the ␥-N-methyl group on Asn72 (1). It has been reported that PBP can sensitize the formation of reactive oxygen species (25,26,63) and that PBP are sensitive to bleaching by reactive oxygen species (21,60,63). In future studies we will determine whether PBP lacking methylation at Asn71/72 produce more reactive oxygen species, whether the PBP themselves are more sensitive to reactive oxygen species, or both.…”

Section: Distribution Of Cpcm and Its Relationship To Other Methyltramentioning

confidence: 95%

CpcM Posttranslationally Methylates Asparagine-71/72 of Phycobiliprotein Beta Subunits in Synechococcus sp. Strain PCC 7002 and Synechocystis sp. Strain PCC 6803

et al. 2008

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Cyanobacteria produce phycobilisomes, which are macromolecular light-harvesting complexes mostly assembled from phycobiliproteins. Phycobiliprotein beta subunits contain a highly conserved ␥-N-methylasparagine residue, which results from the posttranslational modification of Asn71/72. Through comparative genomic analyses, we identified a gene, denoted cpcM, that (i) encodes a protein with sequence similarity to other S-adenosylmethionine-dependent methyltransferases, (ii) is found in all sequenced cyanobacterial genomes, and (iii) often occurs near genes encoding phycobiliproteins in cyanobacterial genomes. The cpcM genes of Synechococcus sp. strain PCC 7002 and Synechocystis sp. strain PCC 6803 were insertionally inactivated. Mass spectrometric analyses of phycobiliproteins isolated from the mutants confirmed that the CpcB, ApcB, and ApcF were 14 Da lighter than their wild-type counterparts. Trypsin digestion and mass analyses of phycobiliproteins isolated from the mutants showed that tryptic peptides from phycocyanin that included Asn72 were also 14 Da lighter than the equivalent peptides from wild-type strains. Thus, CpcM is the methyltransferase that modifies the amide nitrogen of Asn71/72 of CpcB, ApcB, and ApcF. When cells were grown at low light intensity, the cpcM mutants were phenotypically similar to the wild-type strains. However, the mutants were sensitive to high-light stress, and the cpcM mutant of Synechocystis sp. strain PCC 6803 was unable to grow at moderately high light intensities. Fluorescence emission measurements showed that the ability to perform state transitions was impaired in the cpcM mutants and suggested that energy transfer from phycobiliproteins to the photosystems was also less efficient. The possible functions of asparagine N methylation of phycobiliproteins are discussed.

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“…The formation of nanoparticles on RPE is an interesting phenomenon in itself, because such particles have unique photophysical and chemical properties, which make possible their application in optics, the electronic industry, photocatalysis, etc. Moreover, studies are carried out on use of phycobiliproteins for photodynamic treatment of tumors, because they have proven to be more efficient than commonly used hematoporphyrin derivatives [9]. The photodynamic effect can be enhanced significantly if phycobiliproteins are used in combination with a semiconductor, CdS.…”

mentioning

confidence: 99%

R-Phycoerythrin: A natural ligand for detoxifying cadmium ions and a tunnel matrix for synthesis of cadmium sulfide nanoparticles

Bekasova

Brekhovskikh

Brykina

et al. 2005

Appl Biochem Microbiol

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As evidenced by ion-selective electrode potentiometry, the hexameric R -phycoerythrin (RPE) molecule binds 20-4000 cadmium ions (Cd 2+ ) depending on Cd 2+ concentration in the solution. Cadmium ions bound to RPE serve as the nuclei of cadmium sulfide crystallization in the presence of sulfide ions. According to spectrometric, electron-microscopic, and capillary electrophoresis data, the particles are heteroaggregates of 3.2 × 6 nm in size. The fact that the particle size fits the size of the central tunnel of the RPE molecule and the similarity between the electrophoretic patterns of free RPE and the RPE-CdS complex indicate that the tunnel space, limiting the crystal growth, is the most probable site of nanoparticle formation. Properties of the nanoparticles can be modified by changing temperature, pH, etc. It is concluded that RPE can be used as a reagent for detoxification of cadmium ions and a matrix for synthesis of elongated CdS nanoparticles.

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Photodynamic action of phycobiliproteins: in situ generation of reactive oxygen species

Cited by 57 publications

References 19 publications

Antitumor function and mechanism of phycoerythrin from Porphyra haitanensis

Antitumor function and mechanism of phycoerythrin from Porphyra haitanensis

CpcM Posttranslationally Methylates Asparagine-71/72 of Phycobiliprotein Beta Subunits in Synechococcus sp. Strain PCC 7002 and Synechocystis sp. Strain PCC 6803

R-Phycoerythrin: A natural ligand for detoxifying cadmium ions and a tunnel matrix for synthesis of cadmium sulfide nanoparticles

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