Further studies and biological activities of macromolecular protein R-Phycoerythrin from Portieria hornemannii.

In the present study, the purified R-Phycoerythrin (R-PE) from a red alga Portieria hornemannii was subjected to the analysis of stability under the influence of different agents. Among the various inhibitors tested on R-PE EDTA at lower concentrations (<1 mM) supported the activity of R-PE. When R-PE was exposed to different organic solvents, ethanol supported the activity at the maximum followed by acetone, ethyl acetate, chloroform and methanol. Citric acid, as a preservative maintained the stability of R-PE both under 0 ± 5 °C and 30 ± 5 °C with 59.34% and 56.23% respectively, on 30th day. Thermal decomposition of the R-PE began near 60 °C. Maximum weight loss was occurred between 150 °C and 500 °C. Complete weight loss was recorded around 875 °C. Thermal denaturation was observed between 19 °C and 40 °C. Moderate to low antioxidant activities were observed in R-PE in relation to total antioxidant activities. After characterization, R-PE was taken for in vitro anticancer studies against selected cancer cell lines. Further studies involving AO/EB fluorescence staining and phase contrast microscope revealed characteristic apoptotic features like cell shrinkage, membrane blebbing, and nuclear DNA fragmentation, etc. Likewise, FACS analysis revealed the cell cycle distribution pattern of A549 and HepG2 cells.

Stabilization of mitochondrial and microsomal function of fucoidan from Sargassum plagiophyllum in diethylnitrosamine induced hepatocarcinogenesis.

Crude fucoidan from Sargassum plagiophyllum extracted from blade and purified by Q-Sepharose fast flow anion-exchange chromatography and three fucoidan fractions were obtained. Maximum sulphate containing fucoidan fraction was considered as purified fucoidan and purity was checked with agarose gel electrophoresis. The monosaccharides of purified fucoidan analysed by HPLC revealed the presence of the sugars such as fucose as a major sugar were 70.8 mol%. The percentages of other sugars were galactose (13.5%), xylose (2.5%) and mannose (11.2%). GPC was used to analyse molecular weight of purified fucoidan and it was found to be 35 kDa. The levels of ICDH, SDH, MDH, a-KGDH, Phase-I biotransformation enzymes, and Phase-II biotransformation enzymes were decreased in cancer bearing animals which may be due to oxidative stress and mitochondrial damage and fucoidan restored these enzyme activities. The inhibition of carcinogen metabolic activation indicates the anticancer activity of fucoidan in DEN induced liver cancer.

Isolation and characterization of macromolecular protein R-Phycoerythrin from Portieria hornemannii.

R-Phycoerythrin (R-PE) is one of the three phycobiliproteins which are extensively used as fluorescent probes, and it is prepared from red macro-algae. This macromolecular protein has gained importance in many biotechnological applications in food science, immunodiagnostic, therapy, cosmetics, protein and cell labeling, and analytical processes. In the present investigation, R-PE was isolated and purified from a red alga Portieria hornemannii. R-PE extracted and purified through ammonium sulfate precipitation (55%) followed by Q-Sepharose column chromatography had yielded a maximum purity of 5.2%. R-PE exhibited a typical "three-peak" with absorption maxima at 499, 545 and 565 nm. CD spectrum of R-PE yielded the following secondary structure data: alpha helix (14.30%), beta helix (28.10%), turn helix (19.20%) and random coil helix (38.40%). The molecular mass of R-PE was 240 kDa under Native-PAGE. Three different subunits such as α, ß and γ of 16 kDa, 21 kDa and 39 kDa were segregated under SDS-PAGE. On two dimensional gel electrophoresis, one basic and four acidic subunits were detected. Five different tryptic peptides were assigned under MALDI-TOF. The sequences of N-terminus of R-PE of 10 different amino acids are Met Lys Gln Met Trp Asp Arg Met Val Val. The preparative procedures of the R-PE extraction and purification established based on the experiments exhibit advantages and can offer a reference for R-PE preparation from other marine red macro-alga P. hornemannii.