China ; Crystallography, X-Ray ; Light-Harvesting Protein Complexes ; chemistry ; metabolism ; Photosynthesis ; Spinacia oleracea ; chemistry ; metabolism

Phycoerythrocyanin(PEC) lyase-isomerase PecE/PecF from Mastigocladus laminosus is the specific enzyme for biosynthesis of PEC alpha-subunit(alpha-PEC). In this work, the specificity of PecE/PecF on substrate apoproteins was reported. PecE/PecF could catalyse the reconstitution of phycocyanobilin(PCB) with apoproteins of alpha-PEC from two different subspecies of Mastigocladus laminosus, as well the site-directed mutated apoprotein of alpha-PEC with Trp at 128 to Phe in vitro, but could not catalyse the reconstitution of PCB with apoprotein of phycocyanin alpha-subunit(alpha-CPC) from Mastigocladus laminosus. The surfactant Triton X-100 had no effect for the reconstitution of alpha-PEC, while it could improve the reconstitution of PCB with apoprotein of alpha-CPC.
Apoproteins ; metabolism ; Bacterial Proteins ; Catalysis ; Cyanobacteria ; enzymology ; Light-Harvesting Protein Complexes ; Lyases ; metabolism ; Octoxynol ; pharmacology ; Proteins ; metabolism ; Substrate Specificity

We studied the effect of photodynamic therapy with phycobiliproteins on human liver cancer cells in vitro. With 3-(4, 5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT assay), we used two phycobiliproteins, R-phycoerythrin (R-PE) and C-phycocyanin (C-PC) prepared from Porphyra yezoensis, to determine the killing rates and apoptosis rates of human liver cancer cells (SMMC-7721) mediated by laser. When the concentration of R-PE was 120 mg/L, the survival rate of human liver cancer cells was 27% after treated by Argon laser with 100 J/cm2 doses, while the survival rate in the control group (without adding R-PE) was 65%. When the C-PC concentration was 120 mg/L, the survival cell rate was 47% after treated by He-Ne laser with 35 J/cm2 dose, while the survival rate in the control group (without adding C-PC) was 70%. After handled only with these two kinds of phycobiliproteins for 72 h, the growth of cancer cells presented significant inhibition. The maximal inhibition rates reached up to 31% with R-PE (120 mg/L concentration) and 27% with C-PC (250 mg/L concentration) respectively. After irradiated by laser for 8 h, the maximal cell apoptosis rates were 31.54% with R-PE and 32.54% with C-PC, respectively. It indicated that R-PE and C-PC extracted from Porphyra yezoensis could develop to new photosensitizers for cancer photodynamic therapy.
Apoptosis ; drug effects ; radiation effects ; Cell Line, Tumor ; Humans ; Lasers ; Liver Neoplasms ; pathology ; Photochemical Processes ; Photochemotherapy ; methods ; Phycobiliproteins ; isolation & purification ; pharmacology ; Phycoerythrin ; isolation & purification ; pharmacology ; Porphyra ; chemistry

Photosynthesis in plants directly affects the synthesis and accumulation of organic matter, which directly influences crop yield. RNA-binding proteins (RBPs) are involved in the regulation of a variety of physiological functions in plants, while the functions of RBPs in photosynthesis have not been clearly elucidated. To investigate the effect of a glycine-rich RNA-binding protein (SlRBP1) in tomato on plant photosynthesis, a stably inherited SlRBP1 silenced plant in Alisa Craig was obtained by plant tissue culture using artificial small RNA interference. It turns out that the size of the tomato fruit was reduced and leaves significantly turned yellow. Chlorophyll(Chl) content measurement, Chl fluorescence imaging and chloroplast transmission electron microscopy revealed that the chloroplast morphology and structure of the leaves of tomato amiR-SlRBP1 silenced plants were disrupted, and the chlorophyll content was significantly reduced. Measurement of photosynthesis rate of wild-type and amiR-SlRBP1 silenced plants in the same period demonstrated that the photosynthetic rate of these plants was significantly reduced, and analysis of RNA-seq data indicated that silencing of SlRBP1 significantly reduced the expression of photosynthesis-related genes, such as PsaE, PsaL, and PsbY, and affected the yield of tomato fruits through photosynthesis.
RNA ; Solanum lycopersicum/genetics* ; Photosynthesis/genetics* ; Chlorophyll ; RNA-Binding Proteins/genetics*

We developed large-scale preparation of phycoerythrin from Porphyra haitanensis, a main economic red algae in China. Firstly, P. haitanensis thallus was broken by using "swelling and smash" method. Then times of grads ammonium sulfate precipitation applied to the crude extraction were compared. Desalted solution was further purified with one-step chromatography using hydroxyapatite and properties on spectrum and molecular weight were identified finally. The results indicated that after four times of ammonium sulfate precipitation (15%, 50%, 10% and 40%), the absorption spectrum purity of P. haitanensis achieved 0.9 (A564/A280), and 507.82 mg phycoerythrin (A564/A280 > 3.2) was obtained from 7 kg fresh algae after further hydroxyapatite chromatography. This research provides a potential way for preparation of phycoerythrin in large sclae.
Ammonium Sulfate ; chemistry ; Chromatography ; methods ; Phycoerythrin ; isolation & purification ; Porphyra ; chemistry

No abstract available.
Fibrosis ; Inflammation ; Phycocyanin

Flow cytometry, a useful tool for measuring DNA content and cell differentiation as expressed by cell surface markers, is utilized to measure multiple antigens, especially surface antigen, intracellular oncoprotein, and DNA content, simultaneously. For this simultaneous detection, several methods off ixation and permeabilization have been used with limited values. In this study, 20 ng/ml of lysolecithin in 1% paraformaldehyde solution was utilized for fixation and permeabilization of cultured promyelocytic leukemic cells(HL 60). The cells were first stained with phycoerythrin (PE)-conjugated monoclonal antibody to the cell surface My 7 antigen and then were fixed and permeabilized with 20 ng/ml of lysolecithin in 1% partormaldehyde solution. After incubation, the fixed and permeabilized cells were stained with monoclonal antibody to intracellular c-myc antigen, which were followed by fluorescein isothiocyanate (FITC)-conjugated secondary antibody. The c-myc stained cells were finally stained for DNA content with 7-amino-actinomycin D(7-AAD). This procedure permits excellent staining for intracellular oncoproteins and preservation of surface antigens with relatively low cofficients of variation (CV) for the G0G1 peak of the DNA histograms and suggests that the sequential staining procedure of surface antigen, intracellular antigen, and DNA content will be extended for the study of correlations with cellular differentiation, expression of oncoproteins, and cell cycle analysis in the cells which are obtained from human malignant diseases using a 488 nm single laser flow cytometry.
Antigens, Surface* ; Cell Cycle ; Cell Differentiation ; DNA* ; Flow Cytometry* ; Fluorescein ; Humans ; Oncogene Proteins ; Phycoerythrin

OBJECTIVE: This study was designed to estimate the chemosensitivity by a quantitative evaluation of the apoptotic cell fractions using flow cytometry. METHODS: The OVCAR-3 cells were exposed to 20 nM or 30 nM taxol for 0 (control), 24 and 48 hours, then removed the taxol contained media, and cultured further with fresh media without taxol. (1) Fluorescein isothiocyanate-conjugated Annexin V (Annexin V-FITC) and propidium iodide (PI) were added to one test tube to detect the apoptotic cell fractions and at the same time, PI was added to the other tube to stain the DNA. (2) Annexin V-FITC and cytokeratin (clone CAM5.2 and MNF116) were added to the test tube. They were fixed and permeabilized with 1% paraformaldehyde solution and 100% methanol. They were then incubated with phycoerythrin (PE)-conjugated goat anti-mouse immunoglobulin G (GAM IgG1-PE or GAM IgG2a-PE) and sequentially stained with PI for DNA. All the stained cells were analyzed by a FACScan flow cytometer. RESULTS: (1) After treatment of 20 nM or 30 nM of taxol, G2M arrest was observed in both of treatment groups, which increased with time. (2) The G0G1 sub-fraction indicative of apoptosis increased with increase of culturing time from 24 hrs to 48 hrs. (3) The early apoptotic cell fraction with positive annexin V-FITC and negative PI increased with increase of culturing time. (4) In cells stained sequentailly with annexin V-FITC, cytokeratin (CAM5.2 and MNF116), and PI after 30 nM taxol treatment, the early apoptotic cell fractions increased with increase of culturing time. However, their extent was somewhat lower than those observed by positive annexin V-FITC and negative PI in cells treated with 20 nM of taxol. CONCLUSION: The results of sequential stainings with annexin V-FITC, cytokeratin, and PI were consistent with the those of annexin V-FITC and PI with parallel DNA staining. Our results suggested that the level of apoptosis detected by flow cytometry could be a marker of chemosensitivity which could select the sensitive anti-cancer agents before administration to gynecologic cancer patients.
Annexin A5* ; Apoptosis* ; Cell Line* ; DNA ; Evaluation Studies as Topic ; Flow Cytometry ; Fluorescein ; Goats ; Humans ; Immunoglobulin G ; Keratins* ; Methanol ; Ovarian Neoplasms* ; Paclitaxel ; Phycoerythrin ; Propidium*

OBJECTIVE: Taxol (paclitaxel)-induced apoptosis was studied to understand their biological mechanism correlated with the expression of p53 in the SKOV-3 and OVCAR-3 ovarian cancer cell lines. MATERIALS AND METHODS: The SKOV-3 and OVCAR-3 cell lines were cultured in RPMI 1640 medium without taxol (control group) and with taxol for 24 h and 48 h (experimental group). After harvest, the cells were stained with annexin V-FITC (fluorescein isothiocyanate) and anti-cytokeratin antibodies (clone CAM5.2 and clone MNF116). They were washed and stained with p53 antibody. After then the secondary antibodies, i.e., FITC- or phycoerythrin (PE)-conjugated goat anti-mouse (GAM) immunoglobulin G (GAM IgG-FITC or GAM IgG-PE) were added in the cells and they were incubated in the dark. DNA of these cells were stained sequentially with propidium iodide (PI). Standard FACScan equipped with a 488 nm single laser was used for the analysis of these cells. RESULTS: Both of SKOV-3 and OVCAR-3 cell lines were arrested in the G2M phase after treatment of taxol, suggesting that these cells would eventually enter into the stage of cell death. Fractions of negative cytokeratin and positive annexin V and amount of sub-G0G1 fraction indicative of apototic fractions were lower in the SKOV-3 cell line compared with that in OVCAR-3 cell line, probably as a result of lower sensitivity of SKOV-3 cell line to the taxol. p53 expression were not detected in SKOV-3 cell line. On the basis of observed findings in SKOV-3 cell line and findings of high expressions of p53 regardless of taxol treatment, no increases in their expressions according to culturing time, and gradual increases in sub-G0G1 fractions and in fractions of negative cytokeratin and positive annexin V indicative of apoptosis in OVCAR-3 cell line, we concluded that the expression of p53 would not be associated with cell cycle changes and the arrest in the G2M pahse but associated with the appearance of apotosis. CONCLUSION: Our results suggest that flow cytometric detection of the apoptotic fractions would be an effective, fast, and accurate method for the chemosensitivity test in tumor cells before the administration of anti-cancer drugs in gynecologic cancer patients.
Annexin A5 ; Antibodies ; Apoptosis* ; Cell Cycle ; Cell Death ; Cell Line* ; Clone Cells ; DNA ; Flow Cytometry ; Goats ; Humans ; Immunoglobulin G ; Keratins ; Ovarian Neoplasms* ; Paclitaxel ; Phycoerythrin ; Propidium

BACKGROUND AND OBJECTIVES: The thioredoxin (TRx) system is a ubiquitous thiol oxidoreductase pathway that regulates cellular reduction/oxidation status. Although endothelial cell (EC) hypoxic damage is one of the important pathophysiologic mechanisms of ischemic heart disease, its relationship to the temporal expression pattern of the TRx system has not yet been elucidated well. The work presented here was performed to define the expression pattern of the TRx system and its correlation with cellular apoptosis in EC lines in hypoxic stress. These results should provide basic clues for applying aspects of the TRx system as a therapeutic molecule in cardiovascular diseases. SUBJECTS AND METHODS: Hypoxia was induced with 1% O2, generated in a BBL GasPak Pouch (Becton Dickinson, Franklin Lakes, NJ, USA) in human endothelial progenitor cells (hEPC) and human umbilical vein endothelial cells (HUVEC). Apoptosis of these cells was confirmed by Annexin-V: Phycoerythrin flow cytometry. Expression patterns of TRx; TRx reductase; TRx interacting protein; and survival signals, such as Bcl-2 and Bax, in ECs under hypoxia were checked. RESULTS: Apoptosis was evident after hypoxia in the two cell types. Higher TRx expression was observed at 12 hours after hypoxia in hEPCs and 12, 36, 72 hours of hypoxia in HUVECs. The expression patterns of the TRx system components showed correlation with EC apoptosis and cell survival markers. CONCLUSION: Hypoxia induced significant apoptosis and its related active changes of the TRx system were evident in human EC lines. If the cellular impact of TRx expression pattern in various cardiovascular tissues under hypoxia or oxidative stress was studied meticulously, the TRx system could be applied as a new therapeutic target in cardiovascular diseases, such as ischemic heart disease or atherosclerosis.
Anoxia ; Apoptosis ; Atherosclerosis ; Cardiovascular Diseases ; Cell Hypoxia ; Cell Survival ; Endothelial Cells ; Flow Cytometry ; Human Umbilical Vein Endothelial Cells ; Humans ; Lakes ; Myocardial Ischemia ; Oxidative Stress ; Phycoerythrin ; Stem Cells ; Thioredoxins