Research Of Large-scale Preparation, Structure Identification And Anti-cancer Effect Of Phycoerythrin From Porphyra Haitanensis

Phycoproteins are important chromoproteins from algea which can absorb andtransfer light energy. Phycoproteins have a series of biological activities, some of whichused in biomedical engineerings are better than those of other similar materials.phycoerythrin is widely researched among all the four phycoproteins. Porphyrahaitanensis contains rich phycoerythrin, and it is the main cultivative algae forcommerce which produced in our country, therefore, it is perfect to purify and researchphycoerythrin from Porphyra haitanensis.1. Method of large-scale preparation of phycoerythrin from Porphyra haitanensis,a main economic red algae in China was developed. Firstly, P. haitanensis thallus wasbroken using “swelling and smash” method. Then co-precipitation of protein withammonium sulfate were applied to the crude extraction. Solution was further desaltedand purified using hydroxyapatite chromatography and identified on spectrumabsorption and electrophoresis finally. The results indicated that after four times ofco-precipitation with ammonium sulfate (15%,50%,10%and40%), the absorptionspectrum purity of P. haitanensis achieved0.9(A564/A280), and507.82mg phycoerythrin(A564/A280>3.2) was obtained from7kg fresh algae after further hydroxyapatitechromatography. This method provided a potential way for large sclae preparation ofphycoerythrin from algae.2. To sequence and analyse α and β subunit gene of phycoerythrin from Porphyrahaitanensis grown in Fuding city, Fujian Province. DNA extracted from fresh Porphyrahaitanensis was processed with PCR and electrophoresis using primers designedaccording to reported phycobiliprotein conserved sequence.1595bp nucleic acidsequences containing α and β subunit gene of phycoerythrin(accession numberHM008260.1) was obtained after sequencing. The structure of the sequence was analyzed. Physical and chemical parameters, functional sites and spatial configurationof subunits were forecasted. The taxonomic status of Porphyra haitanensis was finallydiscussed based on the characteristic of open reading frame, promoter and SD sequencein the sequences.3. Inhibiton of phycoerythrin from Porphyra haitanensis on cell BEL-7402wasstudyed. PE at different concentrations were irradiated under LED light and argon ionlaser. It was indicated that PE irradiated under laser light were denatured resulting fromthe heavy dropping of absorption peak. Survival ratio of BEL-7402cell reaches20%after72h irradiation under laser light using240μg/mL PE. The inhibiton ratioes of LEDlight and laser light PDT were20%and74%respectively.