Studies On Primary Structure And Comformation As Well As Antioxidation Activities Of Phycocyanin From Nostoc Sphaeroids Kutz

The significant biological and apply value of Nostoc Sphaeroids kutz with abound nutrition and infrequent distribution had been paid people's much attention. Although NSK as a kind of food and medicine function had been used for several thousand years, the main active component of activity and function is little investigated. In recent years, it was by a few people that its partial physiology and primary biochemistry composition was reported. In order to ascertain the active component of NSK, the phycocyanin was used as material, taking advantage of modern separation technology and biomacromolecules analysis method, first systemically studies on preparation and purification of NSPP, and its primary structure and high structure were also investigated. The main results were shown as follows:1 The biological trait of NSK and its biochemisty componentOn the basis of the biological trait of NSK having been investigated, in order to determine its biochemistry components, such as ecological condition and its contribution, Reproduction mechanism, water, protein, fat, polysaccharide, carotene and chlorophyll as well as mineral element, wild NSK, Zouma town, Hefeng county, Hubei province, was used as crude material.2 Extraction, separation, purification and identification of phycocyaninDefatted NSK as material, albumin, globin and salt-soluble protein were separated from NSK by salting-in and salting-out methods for the first time and the the optimal extraction technology were studied. The results were as follows: pH 7.0, salt concentration 0.2 mol/L and extracted time was 4 h, and the output of phycobiliproteins was 7.13 percent. DEAE-Cellulose ion-exchange chromatography was used to separation NSPP. It was successful to obtain five fractions, by the step gradient. NSPP was further purified by DEAE-Separose FF and HA chromatography. Some methods such as spectrophotometer and chromatography and electrophoresis were applied to identify the purity of phycocyanin, and it was identified to be chromatography and electrophoresis grade pure.3 Primary structure characterization of phycocyaninThe primary structure of phycocyanin was studied with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and sodium dodecyl sulfate ployacrylamide gel electrophoresis (SDS-PAGE), its molecular weight and their peptide mass fingerprinting were analysed. The results demonstrated that the measured molecular weight of phycocyanin was 37.715Kd, and consisted of two peptides which were similar with their molecular weight and amino acid sequences.4 The comformation of phycocyaninPhycocyanin high structure was investigated, as the result of circular dichroism (CD) spectrum and Fourier transformation infared (FTIR) spectrum shown, the secondary structure of NSPC was mainlyα-helix structure and the content ofβ-shee or coil was very small. While NSPC's agglutination form was observed by force atom microscope (AFM) and scan electron microscope (SEM) there existed mainly catenulate distribution. Meanwhile, they denatured temperature was also studied by differential scan calorimeter (DSC), the results showed that the temperatute of NSPC 41.6℃.It was shown by fluorescence spectrum that there were both the Trp residues which lie outside the molecular and the Trp residues which lie in the inside hydrophilic structure in NSPC.5 The stability of protions in NSPThe effect of temperature, pH, light intensity, alcohol concentration, difffrent concentration of neutral salt, different saturation ammonium sulfate solution and sucrose concentration on the stability of protions in NSP was investigated. The results showed that, protions in NSP kept still stability under the appropriate circumstance: under natural sunlight, below 40℃, pH 5-8, alcohol concentration＜40°, and 60% aturation ammonium sulfate solution was beneficial to stability. 6 Antioxidation activity of phycocyaninExperiments about the anti-oxidation effect in non-lipidosome and in vitro mice all indicated anti-oxidation activity of NSPP was significantly. The results showed that scavenge capability was orderly, H₂O₂ radical,·OH radical. O₂^- radical with chemiluminescence, respectively. Through the experiment in vitro, Phycocyanin could reduce the content of MAD and LOP in blood and liver.