The phycocyanin-chlorophyll-protein complexes isolated from Chroomonas placoidea

An active photosystem(PS)Ⅱparticle and two light-harvesting complexes,as well as their subcomplexes that have not been reported previously,were isolated from a cryptophyte Chroomonas placoidea by Triton X-100 sucrose density gradient centrifugation.The fluorescence spectra revealed that there were efficient energy couplings between phycocyanin(PC645)and chlorophyll(Chl)within both zonesⅢandⅣof the gradient,which were designated respectively as light-harvesting complex and PSⅡparticles whose size was 15-20 nm according to negative staining in electron microscopy.When the two complexes were further resolved into sub-complexes,the energy coupling was retained in the core PSⅡcomplex(named as zoneⅣ-2 of the sucrose gradient),which contained almost no outer antenna pigment Chl c.Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)showed that the PC645 components appeared in Chl-containing protein complexes were mainly the β subunit with molecular weight of 20 kDa.These results demonstrate that PC645 in this cryptophyte was structurally but preferentially combined with the light-harvesting complex and PSⅡcore.The excitation energy absorbed by PC645 could be directly transferred to Chl a(especially the long wavelength of Chl a)in the PSⅡreaction center or via the Chl a/c-protein complex.The β subunit corresponded to the terminal fl uorescence emission and might play an important role in transmitting energy from PC645 to the Chl-protein complex.The results will help in elucidating the architecture and function of the energy transfer system comprising phycobiliproteins and Chl-protein complexes in cryptophytes.

Subunit composition and chromophore content of R－phycocyanin and allophycocyanin from Porphyra haitanensis

R-phycocyanin (RPC) of Porphyra haitanensis (T. J. Chang et B. F. Zheng )' was chromatographed on Bio-Rex 70 column with urea solution (pH 3. 0) as an eluent, and a and β two subunits were isolated.Their molecular weights were determined on SDS-PAGE at 18 400 and 20 500, respetively,while those of a and β subunits of allophycocyanin (APC) at 18 800 and 19 700, respectively,and those of RPC and APC were at 117 000 and 122 000,respectively.Both the molar ratio of a and β subests of RPC and APC were 1:1, and the subunit composition was confirmed to be (αβ )3.It was ascertained that in RPC αsubunit contains one chromophore phycocyanobilin (PCB) and β subunit has one chromophore PCB and one phycoerythrobilin (PEB), while in APC both α and βsubunits contain one PCB.

A novel phycocyanin-Chla/c_2-protein complex isolated from chloroplasts of Chroomonas placoidea

Nine pigment-protein complexes were separated and characterized from intact Chroomonasplacoidea chloroplasts by IEF. The bands Ⅰ-Ⅵ with their isoelectric points （pI） values from 4 to 6 were phycocyanin components; bands Ⅷ and Ⅸ （pI = 2.8-3.6） were chlorophyll-protein complexes. According to absorption and fluorescence spectra, band VII was designated as a novel phycocyanin-Chla/c2-protein complex （pI ≈ 3.4-3.7）. These results indicated that phycocyanin is structurally and functionally coupled with chlorophyll-protein complex in C. placoidea, and probably interacted with electrostatic force in combination.

Phycocyanin attenuates X-ray-induced pulmonary inflammation via the TLR2-MyD88-NF-κB signaling pathway

Phycocyanin (PC), a natural algal protein, is reported for having anti-oxidant and antiinfl ammatory properties. We investigated its ability to attenuate lung infl ammation in mice subjected to X-ray radiation. Male C57BL/6 mice were assigned to the control, total body irradiation, PC pretreatment, and PC treatment groups. Mice in the PC pretreatment group were gavaged with 200 mg/kg PC for 7 consecutive days before irradiation, and those in the PC treatment group were gavaged with 200 mg/kg PC for 7 consecutive days after irradiation. Lungs were collected on Day 7 after irradiation exposure. Hematoxylin and eosin staining of mouse lung sections showed considerable infl ammation damage 7 days after irradiation compared with the control lung but a reduction in pathological injury in the PC treatment group. Pretreatment or treatment with PC signifi cantly decreased levels of interleukin-6 and tumor necrosis factor-α in the lung, and also increased the relative mRNA expression of superoxide dismutase and glutathione. In vivo, PC signifi cantly reduced the expression of Toll-like receptor TLR2, myeloid diff erentiation primary response Myd88, and nuclear factor NF-κB, at both the transcriptional and translation level. Taken together, these data indicated that PC attenuated lung infl ammatory damage induced by radiation by blocking the TLR2- MyD88-NF-κB signaling pathway. Therefore, PC could be a protective agent against radiation-induced infl ammatory damage in normal tissues.

Purification and Photodynamic Bioactivity of Phycoerythrin and Phycocyanin from Porphyra yezoensis Ueda

Phycoerythrin and phycocyanin were purified from Porphyra yezoensis Ueda with their bioactivity determined in this study. Continuous precipitation with ammonium sulfate at different concentrations(10%, 20%, 40% and 50%) increased the purity(A564:A280) of phycoerythrin to 1.49, 3.92 fold of the raw extract(0.38) and the purity(A615:A280) of phycocyanin to 0.70, 3.33 fold of the raw extract(0.21). Two more times of chromatography with hydroxylapatites finally made the purity of phycoerythrin and phycocyanin reach 5.50, 14.47 fold of the raw extract, and 5.10, 24.29 fold of the raw extract, respectviely. The yield of high purity phycoerythrin and phycocyanin were 0.21% and 0.09% of dried P. yezoensis blade, respectively. The photodynamic cytotoxic experiment showed that both phycoerythrin and phycocyanin inhibited the growth of liver tumor cells significantly. It was found that 250 mg L-1 purified phycoerythrin and phycocyanin inhibited the growth of hepatocellular carcinoma cells 24 h after laser-irradiation by 80% and 59%, respectively, and 100 mg L-1 purified phycoerythrin and phycocyanin induced the apoptosis of 31.54% and 32.54% of the cells, respectively, 8 h after photodynamic therapy. Oue findings demonstrated that P. yezoensis can serve as photosensitizer(phycoerythrin and phycocyanin) producer.

Alternative Methods for Analysis of Cyanobacterial Populations in Drinking Water Supplies: Fluorometric and Toxicological Applications Using Phycocyanin

The management of cyanobacteria and potential exposure to associated biotoxins requires the allocation of scarce resources across a range of freshwater resources within various jurisdictions. Cost effective and reliable methods for sample processing and analysis form the foundation of the protocol yielding reliable data from which to derive important decisions. In this study the utilization of new methods to collect, process and analyze samples enhanced our ability to evaluate cyanobacterial populations. Extraction of phycocyanin using the single freeze thaw method provided more accurate and precise measurements (CV 4.7% and 6.4%), offering a simple and cost-effective means to overcome the influence of morphological variability. In-vacuo concentration of samples prior to ELISA analysis provided a detection limit of 0.001 μg·L?1 MC. Fractionation of samples (?1) = ?0.279 + (1.368 ? Log PC (μg·L?1) while in an Aphanizomemon spp. dominant system Log MC (ng·L?1) = 0.385 + (0.449 ? Log PC (μg·L?1). These methods and sampling protocol could be used in other aquatic systems across a broader regional landscape to estimate the levels of microcystins.

Interventional effect of phycocyanin on mitochondrial membrane potential and activity of PC12 cells after hypoxia/reoxygenation

BACKGROUND： Phycocyanin can relieve decrease of mitochondrial membrane potential through reducing production of active oxygen so as to protect neurons after hypoxia/reoxygenation. OBJECTIVE： To observe the effect of phycocyanin on activity of PC12 cells and mitochondrial membrane potential after hypoxia/reoxygenation. DESIGN： Randomized controlled study SETTING ： Cerebrovascular Disease Institute of Affiliated Hospital, Medical College of Qingdao University MATERIALS： The experiment was carried out at the Key Laboratory of Prevention and Cure for cerebropathia in Shandong Province from October to December 2005. PC12 cells, rat chromaffin tumor cells, were provided by Storage Center of Wuhan University; phycocyanin was provided by Ocean Institute of Academia Sinica; Thiazoyl blue tetrazolium bromide （MTT） and rhodamine 123 were purchased from Sigma Company, USA; RPMI-1640 medium, fetal bovine serum and equine serum were purchased from Gibco Company, USA. METHODS： ① Culture of PC12 cells： PC12 cells were put into RPMI-1640 medium which contained 100 g/L heat inactivation equine serum and 0.05 volume fraction of fetal bovine serum and incubated in CO2 incubator at 37℃. Number of cells was regulated to 4 × 10^5 L 1, and cells were inoculated at 96-well culture plate. The final volume was 100μL. ② Model establishing and grouping： Cultured PC12 cells were randomly divided into three groups： phycocyanin group, model control group and non-hypoxia group. At 24 hours before hypoxia, culture solution in phycocyanin group was added with phycocyanin so as to make sure the final concentration of 3 g/L , but cells in model control group did not add with phycocyanin. Cells in non-hypoxia group were also randomly divided into adding phycocyanin group （the final concentration of 3 g/L） and non-adding phycocyanin group. Cells in model control group and phycocyanin group were cultured with hypoxia for 1 hour and reoxygenation for 1, 2 and 3 hours; meanwhile, cells in non-hypoxia group were cultured with oxygen and were measured at 1 hour after hypoxia/reoxygenation. ③ Detecting items： At 1, 2 and 3 hours after reoxygenation, absorbance （A value） of PC12 cells was measured with MTT technique so as to observe activity and quantity of cells. Fluorescence intensity of PC12 cells marked by rhodamine 123 was measured with confocal microscope in order to observe changes of mitochondrial membrane potential. MAEN OUTCOME MEASURES： Comparisons between quantity and activity of PC12 cells and mitochondria membrane potential at 1, 2 and 3 hours after reoxygenation. RESULTS： ① Effect of phycocyanin on quantity and activity of PC12 cells： A value was 0.924±0.027 in adding phycocyanin group and 0.924±0.033 in non-adding phycocyanin group. A value was lower in model control group and phycocyanin group than that in non-hypoxia group at 1, 2 and 3 hours after reoxygenation （0.817±0.053, 0.838±0.037, 0.875±0.029; 0.842±0.029, 0.872±0.025, 0.906±0.023, P 〈 0.05）. A value was higher in phycocyanin group than that in model control group at 1, 2 and 3 after culture （P 〈 0.05）. With culture time being longer, A value was increased gradually in phycocyanin group and model control group after reoxygenation （P 〈 0.05）. ~ Effect of phycocyanin on mitochondrial membrane potential of PC12 cells： Fluorescence intensity was 2.967±0.253 in adding phycocyanin group and 2.962±0.294 in non-adding phycocyanin group. Fluorescence intensity was lower in model control group and phycocyanin group than that in non-hypoxia group at 1, 2 and 3 hours after hypoxia/reoxygenation （1.899±0.397, 2.119±0.414, 2.287±0.402; 2.191±0.377, 2.264±0.359, 2.436±0.471, P 〈 0.05）; but it was higher in phycocyanin group than that in model control group at 1, 2 and 3 after reoxygenation （P 〈 0.05）. With culture time being longer, fluorescence intensity was increased gradually in phycocyanin group and model control group after reoxygenation （P 〈 0.05）. CONCLUSION： Phycocyanin and reoxygenation can protect PC12 cells after hypoxia injury through increasing mitochondrial membrane potential and cellular activity, and the effect is improved gradually with prolonging time of reoxygenation.

The Stability of C-phycocyanin Doped Silica Biomaterials in UV Irradiation

The synthesized C-phycocyanins （C-PCs） doped silica biomaterials were characterized by the SEM and BET surface area analysis measurement. The morphology of C-PCs doped silica biomaterials indicates that the surface of the silica cluster is formed by a great number of silica particles with an average size of between 30 and 40 nm. Silica itself is a porous structure with the average pore diameter of 2.95 nm. Pores with their diameter less than 5 nm account for 84.07%. In addition, the C-PCs can be utilized as a fluorescent protein probe to monitor influence of the protein encapsulation and to study matrix and protein interaction and stability of protein in silica matrix. Application of protein encapsulation silica materials requires biomolecules to keep bioactivity and stability on potentially unfavorable industrial conditions. The C-PCs in solution or in silicate matrix irradiated by ultraviolet ray can result in photobleaching, whereas the protein in the silica is less affected. The measured photodamage rate constant of C-PCs in buffer solution is 25 times faster than that of C-PCs in silica matrix. However, the lifetime of C-PCs in silica matrix or phosphate buffer is unaffected. These studies suggest that entrapment of C-PCs into silica matrixes not only can maintain their biological activity but also noticeably improve their photostability.

EFFECTS OF PHYCOCYANIN ON EXPRESSION OF CytC mRNA AND CASPASE-3 mRNA AFTER FOCAL CEREBRAL ISCHEMIA/REPERFUSION IN RATS

Objective To study the effects of phycocyanin on the expression of Cytochrome C (CytC)genes and Caspase-3 genes after focal cerebral ischemia/reperfusion in rats. Methods A rat middle cerebral ar-tery occlusion (MCAO)/reperfusion model was produced using the intraluminal filament method. The rats were di-vided into three groups: sham operation group, model control group and phycocyanin group. After MCAO, the neu-robehavioral testing of all rats was made. The infarction area was evaluated with the method of 2,3,7-triphenyltet-razolium chloride (TTC) staining. The expression of CytC mRNA and Caspase-3 mRNA were determined by in situhybridization. Results In the sham operation group and the model control group, there was only a few CytC-positive cells were seen in the normal cerebral tissue. In the model control group, the upregulation of CytC mRNAbegan 6h after ischemia, reached a maximum at 12h (cortex) -24h (striatum) , then subsided gradually, but stillin high level. In the phycocyanin group, CytC-positive cells were also mainly in cortex and striatum, but the numberof the cells was significantly lower than the number of the model control group. The time-phase pattern of CytCmRNA in the phycocyanin group was similar to the pattern of the model control group. In the sham operation groupand the model control group, there was only a few Caspase-3-positive cells were seen in the normal cerebral tissue.In the model control group, the upregulation of Caspase-3 mRNA began 6h after ischemia, reached a maximum at24h and subsided at 48h, but still in high level. In the phycocyanin group, Caspase-3-positive cells were also mainlyin the penumbral area, but the number of the cells were significantly lower than the number of the model controlgroup. The time-phase pattern of Caspase-3 mRNA in the phycocyanin group was similar to the pattern of the modelcontrol group. Conclusion The over-expression of CytC mRNA and Caspase-3 mRNA might play a key role inischemic cerebral injury after MCAO. Phycocyanin could inhibit the over-expression of CytC mRNA and Caspase-3mRNA in the cerebral cortex, and might play an important role in the protection of ischemic neurons.

IRON IONS INCREASE THE THERMOSTABILITY OF PHYCOCYANIN OF SPIRULINA MAXIMA

A spectral method to investigate the effect of Fe3+, Fe2+ on the thermostability ofphycocyanin (PC) of Spirulina maxima showed that iron ions prevent decrease of visible light absorbanceand fluorescence intensity of PC. Increase in denaturation temperature caused by Fe3+ was observed bythe micro - differential scanning calorimetric method. All results showed iron ions maintain the aggrega-tion stability of the PC. The absorption spectrum of phycocyanobilin (PCB, a prosthetic group of PC) withFe3+ in chloroform was quite different from that of free PCB.

Isolation and Characterization of C-phycocyanin from Spirulina Platensis

The isolation of biliproteins from the Spirulina platensis cultured in southern China was accomplished with gel filtration on Sephacryl S 200 and chromatography on hydroxylapatite. The spectrophotometry, isoelectric point, and amino acid composition of C phycocyanin were determined, respectively.

Physicochemical degradation of phycocyanin and means to improve its stability:A short review

The cyanobacterium Arthrospira platensis,spirulina,is a source of pigments such as phycobiliprotein and phycocyanin.Phycocyanin is used in the food,cosmetics,and pharmaceutical industries because of its antioxidant,anti-inflammatory,and anticancer properties.The different steps involved in extraction and purification of this protein can alter the final properties.In this review,the stability of phycocyanin(pH,temperature,and light)is discussed,considering the physicochemical parameters of kinetic modeling.The optimal working pH range for phycocyanin is between 5.5 and 6.0 and it remains stable up to 45℃;however,exposure to relatively high temperatures or acidic pH decreases its half-life and increases the degradation kinetic constant.Phycobiliproteins are sensitive to light;preservatives such as mono-and disaccharides,citric acid,or sodium chloride appear to be effective stabilizing agents.Encapsulation within nano-or micro-structured materials such as nanofibers,microparticles,or nanoparticles,can also preserve or enhance its stability.

Purification and Antioxidant Activities of Phycocyanin from Spirulina Platensis

This study aimed to purify and determine antioxidant activities of different fractions obtained during the purification process of phycocyanin from Spirulina platensis. The dried powder of Spirulina platensis, after ground with sands, was extracted with 50 mM sodium phosphate buffer at pH 6.8 before centrifuged to precipitate unwanted proteins. Then the supernatant was separated by celit column to obtain semi-pure phycocyanin and further purified by treated with ammonium sulfate. The purity of phycocyanin was monitored by measuring the absorbance spectrum from 200 to 700 nm. Its purity ratio A620A280 was determined. The antioxidant activities of the obtained phycocyanin were determined by 2,2＇-azino-bis（3-ethylbenzthiazoline-6-sulphonic acid） （ABTS） assay and lipid peroxidation （linoleie acid） assay. The purity ratio of phycocyanin in the Spirulina crude extract was 0.36 and increased to 2.68 after purification. The fraction with the highest purity ratio of phycocyanin demonstrated the hightest antioxidant activities. For ABTS assay, it presented the Vitamin C Equivalent Antioxidant Capacity （VCEAC） value of 0.0405 ±0.0002 mg of ascorbic acid/mg of sample and the Trolox Equivalent Antioxidant Capacity （TEAC） value of 0.0485 ±0.0002 mg oftrolox/mg of sample respectively. The result from lipid peroxidation assay exhibited IC50 value of 5.9336 ±0.2565 mg/mL. The purification of Spirulinaplatensis crude extract obtained from this study increased the purity ratio of phycocyanin and its antioxidant activities. This will be further investigated for the development into anti-aging cosmetic products.

Telomere Protective Effects of a Cyanobacteria Phycocyanin against Blue Light and UV Irradiations: A Skin Anti-Aging and Photo-Protective Agent

Background: Cyanobacteria phycocyanins (Cps) have already shown powerful antioxidant properties. In human cells submitted to oxidative stress the telomeres length decrease, the expression of progerin and the activity of mTOR are increased. At our knowledge, there is no published data on Cps correlated with ultraviolet radiation (UV) and blue light effects in human cells regarding telomeres’ length, progerin expression or mTOR1 complex activity. Objectives: In this study, we sought to assess 1) telomeres’ length in newborn human fibroblasts exposed to UV and blue light;2) progerin production in mature human normal fibroblasts exposed to UV;3) mTOR1 activation in adult human normal keratinocytes exposed to UV, analyzing the activity of a Cyanobacteria phycocyanin (Cp) in these in vitro models. Materials and Methods: Human skin fibroblasts or human normal keratinocytes were cultured—in the absence or in the presence of Cp and submitted to UVB + UVA and blue light irradiations. Telomeres’ length, progerin expression and mTOR1 activity were then assessed by molecular biology and immuno-enzymatic methods. Results: In cultured fibroblasts exposed to irradiations and treated by Cp, telomeres’ shortage and progerin expression were lower compared to irradiated untreated cells. In cultured keratinocytes treated by Cp and exposed to irradiations, the mTOR activity was lower compared to irradiated untreated cells. Conclusions: In these in vitro studies on human skin fibroblasts and on normal human keratinocytes, the cyanobacteria phycocyanin (Cp) showed a decrease of damages induced by UV and blue light expressed by telomeres preservation and downregulation of progerin expression and of mTOR activity, thus showing skin anti-aging and photo-protective potential.

Effects of phycocyanin on apoptosis and expression of superoxide dismutase in cerebral ischemia reperfusion injury

BACKGROUND ： The application of exogenous antioxidant is always the focus in the prevention and treatment of cerebral ischemia. Phycocyanin has the effects against oxidation and inflammation, but its role in the pathophysiological process of cerebral ischemia reperfusion injury still needs further investigation. OBJECTIVE： To observe the effects of phycocyanin on the expression of superoxide dismutase （SOD） apoptosis and form of the nerve cells in rats after cerebral ischemia reperfusion injury. DESIGN： A randomized control animal experiment SETTING ： Institute of Cerebrovascular Disease, Medical School Hospital of Qingdao University MATERIALS： Fifty-two healthy adult male Wistar rats of clean degree, weighing 220-260 g, were used. Phycocyanin was provided by the Institute of Oceanology, Chinese Academy of Sciences. METHODS： The experiments were carried out in Shangdong Key Laboratory for Prevention and Treatment of Brain Diseases from May to December 2005. ① All the rats were divided into three groups according to the method of random number table： sham-operated group （n=4）, control group （n=24） and treatment group （n=24）. Models of middle cerebral artery occlusion/reperfusion （MCAO/R） were established by the introduction of thread through external and internal carotid arteries in the control group and treatment group. After 1-hour ischemia and 2-hour reperfusion, rats in the treatment group were administrated with gastric perfusion of phy- cocyanin suspension （0.1 mg/g）, and those in the control group were given saline of the same volume, and no treatment was given to the rats in the sham-operated group. ②The samples were removed and observed at ischemia for 1 hour and reperfusion for 6 and 12 hours and 1, 3, 7 and 14 days respectively in the control group and treatment group, 4 rats for each time point, and those were removed at 1 day postoperatively in the sham-operated group. Forms of the nerve cells were observed with toluidine blue staining. Apoptosis after cerebral ischemia reperfusion was detected with TUNEL technique. SOD expression was detected with immunohistochemical technique.③ The intergroup difference was compared with the ttest. MAIN OUTCOME MEASURES： The apoptosis of the nerve cells and SOD expression were mainly observed in each group. RESULTS： Finally, 52 rats were involved in the analysis of results. ① Number of apoptotic cells： In the sham-operated group, a few apoptotic cells could be observed in brain tissue. The apoptotic cells at each time point in the control group and treatment group were obviously more than those in the sham-operated group （P 〈 0.05）. In the treatment group, the numbers of apoptotic cells at 12 hours, 1 and 3 days after reperfusion were significantly fewer than those in the control group, and those at 6 hours, 7 and 14 days were similar to those in the control group. ② Number of SOD positive cells： In the sham-operated group, there was weak expression of SOD in brain tissue, and the positive cells were extremely few, the positive cells at each time point were significantly more in the control group and treatment group than in the sham-operated group （P 〈 0.05）. In the treatment group, the numbers of positive cells at 6 and 12 hours, 1 and 3 days after reperfusion were significantly fewer than those in the control group, and those at 7-14 days were similar to those in the control group. ③ Cellular forms： In the control group, the karyopyknosis occurred in the nerve cells, which were irregularly distributed, nucleolus disappeared, and some scattered cell fragments were observed. The forms of the nerve cells in the treatment group were generally normal. CONCLUSION ： Phycocyanin plays a neuroprotective role in cerebral ischemia reperfusion injury by activating the SOD expression and inhibiting apoptosis.

Phycocyanin for protecting brain ischemia-reperfusion injury and its effect on the expression of Caspase-3 mRNA

BACKGROUND ; Phycecyanin can anti-oxidize and clear free radial. Whether its protective effect on brain is related to Caspase-3, the promoter and operator of apoptosis, is highly concerned. OBJECTIVE： To observe phycocyanin for protecting nerve function and reducing the size of cerebral infarction of rats with brain ischemia-reperfusion and its effect on the expression of Cespese-3 mRNA. DESIGN ： A randomized controlled experiment. SETTING ： Institute of Cerebrovascular Disease, Affiliated Hospital of Medical College of Qingdao University MATERIALS： Totally 84 adult healthy female Wistar rats, weighing 210 to 250 g, of clean grade, were provided by the Animal Experimental Center of Shandong University. Phycocyanin （Institute of Oceanography of Chinese Academy of Sciences） was used. METHODS： This experiment was carried out in the Key Laboratory for Prevention and Treatment of Brain Diseases during May to December 2005. ① The rats were randomized into sham-operation group （n=4）, control group （n=-40） and phycocyanin-treated group （n=-40）. Middle cerebral artery occlusion/reperfusion （MACO/R） models were created on the rats of control and phycocyanin-treated groups with suture-occluded method by inserting a thread into left side extemal-internal carotid artery. In the sham-operatien group, inserting suture was omitted. After ischemia for 1 hour and reperfusion for 2 hours, suspension of phycocyanin was intragastdcaUy administrated into the rats of the phycocyanin-treated group at 100 mg/kg , and the same volume of normal saline was isochrenously administrated into the rats of control group as the same. ② Six rats were chosen respectively from the control group and phycocyanin-treated group, then neurologic impairment degrees of rats were evaluated according to Bederson＇s grading. ③ Six rats were chosen respectively from the control and phycocyanin-treated groups. The isolated brain tissue was stained with tdphenyltetrazolium chloride, and then the size of cerebral infarction was calculated with HPIAS-1000 image analytical system by calculating the ratio of cerebral infarction size at each layer and contralateral hemisphere size of the same layer. ④ Twenty--eight rats were chosen respectively from the control and phycocyanin-treated groups, Brain tissue was harvested at reperfusion for 6,12,24 hours and for 2,3,7 and 14 days after ischemia for 1 hour, respectively, 4 rats at each time point. Brain tissue of 4 rats of sham-opera- tion group was harvested at the 24^th hour after operation. Brain tissue sections were performed in situ hybridization detection of Cespase-3 mRNA. MAIN OUTCOME MEASURES： Comparison of neurologic impairment degree, cerebral infarction size and the expression of brain tissue Caspase-3 mRNA of rats between two groups RESULTS： Totally 84 rats entered the stage of result analysis. ① Bederson＇s scores at ischemia and reperfusion for 24 and 48 hours were significantly lower in the phycocyanin-treated group than in the control group（P 〈 0.05）. ② After brain ischemia and reperfusion, the infarction area was the largest in the 3^rc layer in both control and phycocyanin-treated group, which was（25.23±0,47）% and（23.09±120） %, respectively, and the size of infarction area in the 2^nd layer to the 5^th layer was significantly smaller in the phycocyanin-treated group than in the control group （P 〈 0.05）. ③Positive cell counts of brain tissue Caspase-3 mRNA： The number of positive cells of Caspase-3 mRNA of control group was increased from cerebral ischemia and reperfusion 6 hours, reached the peak at ischemia and reperfusion 24 hours, began to decrease 2 days later and positive cells of Caspese-3 mRNA were still expressed on the 14^th day after reperfusion. At ischemia and reperfusion 6,12 and 24 hours as well as 2,3,7 and 14 days, positive cell counts of Caspase-3 at peripheral ischemic area were significantly lower in the phycocyanin-treated greup[（70.67 ±3.65）, （85.06±4.79）, （119.54±5.37）,（74.26±2.19）, （62.06±3.34）, （23.11±1.89）, （10.75±2.63）/visual field] than in the control group [（94.38±8 28）, （108.81 ±16.11）, （140.88±14.47）, （98.13±11.31）, （81.03±9.31）, （31.22±8.86）, （16.06±5.96）Nisual field] （ P 〈 0.05）; and those at central ischemic area were also significantly lower in the phycocyanin-treated group [（33.86±4.01）, （39.51±3.46）, （50.96 ±2.53）, （43.07±4.09）, （36.25 ±3.72）, （9.03±3.87）, （4.91±5.59）/visual field ]than in the control group [（51.35±2.13）, （54.87±3.42）, （61.77±4.94）, （55.69±6.06）, （49.01 ±5.73） ,（12.84±3.37）, （7.32±2.39）/visual field]（P 〈 0.05）. CONCLUSION ： Phycocyanin can obviously improve the neurologic function, reduce the size of brain infarction and down-regulate the expression of Caspase-3 mRNA of rats with ischemia and reperfusion injury, thus protect brain.

Effect of Hg(II) and Pb(II) Ions on C-Phycocyanin (<i>Spirulina</i><i>platensis</i>)

Influence of Hg(II) and Pb(II) ions on C-Phycocyanin (C-PC) from cyanobacteria Spirulina platensis was investigated using Fluorescence spectroscopy. Fluorescence measurements demonstrate quenching of C-PC emission by Hg(II) and Pb(II), and blue shifts in the fluorescence spectra. The effect of DNA on the fluorescence of Hg(II)-and Pb(II)-C-PC (from Spirulina platensis) complexes was also studied. It was shown that the fluorescence intensity of Hg-C-PC after addition of DNA gave rise to the fluorescence buildup. At the same time, addition of DNA to the Pb(II)-C-PC complexes showed no such effect. In the case of Hg(II)-C-PC, fluorescence intensity significantly decreases in time, while for Pb(II)-C-PC, decrease of the fluorescence intensity is not significant, but blue shift of the peak takes place.

具尾蓝隐藻(Chroomonas caudata Geitler)研究──Ⅱ.藻蓝蛋白(Phycocyanin)的初步分析

初步分析了具尾蓝隐藻（ChroomonascaudataGeitler）的藻蓝蛋白，其吸收光谱为一双峰曲线，两个吸收峰分别为590nm和640nm。按A．N．Glazer等关于隐藻藻蓝蛋白分型的意见，具尾蓝隐藻的藻蓝蛋白属于Ⅱ型PC－645。

Temporal and Spatial Variations of Abundance of Phycocyaninand Phycoerythrin-Rich Synechococcus in Pearl River Estuary and Adjacent Coastal Area

Three surveys were carried out in Pearl River Estuary and adjacent coastal area in May, August, and November, 2013, to investigate the temporal and spatial variations of abundance of phycoerythrin-rich Synechococcus(PE-rich SYN) and phycocyanin-rich Synechococcus(PC-rich SYN). The effects of environmental factors on the alternation of the different Synechococcus groups were also elucidated. PE-rich SYN was detected in three surveys, whereas PC-rich SYN was detected in May and August, but not in November. The highest abundances of PE-rich SYN and PC-rich SYN were recorded in August and May, with mean values of 74.17×103 and 189.92×103 cells m L-1, respectively. From May to November, the relative abundance of PE-rich SYN increased, whereas that of PC-rich SYN declined. PE-rich and PC-rich SYN presented similar horizontal distributions with high abundance in the southern estuary in May, and in the western estuary in August. The abundances of PE-rich and PC-rich SYN were high at 27–32℃and salinity of 10–20. PC-rich SYN was not detected at < 24℃, and PC:PE-rich SYN decreased in abundance with salinity increase. When less than 20 mg L-1, suspended particulate matter(SPM) was helpful for Synechococcus growth. PE-rich SYN decreased in abundance when the concentration of dissolved inorganic nitrogen increased in May and November, and the concentration of phosphate increased in November. However, PC-rich SYN abundance and nutrients showed no correlation. Principal component analysis and regression analysis indicated that PE-rich SYN significantly correlated with the principal components that were affected by environmental factors.

Construction of energy transfer model of C-phycocyanin and allophycocyanin from Spirulina platensis

PHYCOBILIPROTEINS. which include phycoerythrin, phycocyanin, phycoerythroeyanin and allophycocyanin, are intensively coloured, highly fluorescent, water soluble chromoproteins. They are composed of at least two dissimilar polypeptides, α and β subunits, in a molar ratio of 1:1. The subunits possess linear tetrapyrrole prosthetic groups covalently linked to the primary structure via cysteine thioether linkages. In blue-green and red algae, phycobiliproteins occur in a supramolecular structure, the phycobilisome, located on the surface of thylakoid to