Phycoerythrin （PE） is one of the most important proteins involved in light capturing during photosynthesis in red algae. Its potential biological activities had gained wide concerns. In the present study, tumor cyto...Phycoerythrin （PE） is one of the most important proteins involved in light capturing during photosynthesis in red algae. Its potential biological activities had gained wide concerns. In the present study, tumor cytotoxic and hydroxyl radical assay were preformed to detect the bioactivity of recombinant PE. Recombinant plasmids pGEX-PE and pBGL were transformed into E.coli BL21 to make two recombinant strains BEX （pGEX-PE） and BGL （pBGL）. PE expressing in BEX （pGEX-PE） was validated by SDS-PAGE and Western blotting analysis. SDS-PAGE analysis indicated that the PE-GST fusion protein was mostly inclusion bodies. Specific expression of PE was confirmed by Western blotting analysis. The recombinant E. coli BEX （pGEX-PE） cells were collected and sonicated. The supernatants were reserved for the tumor cytotoxic experiments. The result of tumor cytotoxic assay indicated that the supernatants containing PE had the activity of inhibiting the growth of Hela cells and with the increase of protein concentration, the inhibiting rate increased from 37.31% to 63.26%, which showed significant difference from the control. Hydroxyl radical scavenging effect was tested with supernatants of BEX （pGEX-PE） and BGL （pBGL） cell lysates treated with sonication and heating. For the sonication samples, the scavenging rates of the supernatants of BEX （pGEX-PE） and BGL （pBGL） cell lysates were significantly higher than the negative control BL2 I（pGEX-4T） （P〈0.02）, and the scavenging rates increased slowly following the increase of the protein content. For the heating samples, except for the 0.2 mgmL^-1 BGL （pBGL） products, the scavenging effects of the supernatants of BEX （pGEX-PE） and BGL （pBGL） cell lysates were stronger than that of negative control BL21（pGEX-4T）. However, the effect intensity was not positively correlated with the increase of the protein concentration. Though a partially decreased hydroxyl radical scavenging activity was led by heating, the biological activity展开更多
Gracilaria tenuistipitata varliui Zhang el Xia is cultivated at two different salinities (21, 33) in the laboratory for 4 weeks. The daily growth rate is determined. The total agar yield and fractional agar compositio...Gracilaria tenuistipitata varliui Zhang el Xia is cultivated at two different salinities (21, 33) in the laboratory for 4 weeks. The daily growth rate is determined. The total agar yield and fractional agar composition are analyzed. Results show that algae grow faster in low salinity. The total agar yield is higher under high salinity conditions than under low salinity conditions. Among the eight fractions extracted, the yields of cold water extract and 40% ethanol extract are about the highest In low salinities the yields of autoclaved extract and 60% ethanol extract are higher, while the yield of cold water extract is lower relative to high salinities.展开更多
文摘Phycoerythrin （PE） is one of the most important proteins involved in light capturing during photosynthesis in red algae. Its potential biological activities had gained wide concerns. In the present study, tumor cytotoxic and hydroxyl radical assay were preformed to detect the bioactivity of recombinant PE. Recombinant plasmids pGEX-PE and pBGL were transformed into E.coli BL21 to make two recombinant strains BEX （pGEX-PE） and BGL （pBGL）. PE expressing in BEX （pGEX-PE） was validated by SDS-PAGE and Western blotting analysis. SDS-PAGE analysis indicated that the PE-GST fusion protein was mostly inclusion bodies. Specific expression of PE was confirmed by Western blotting analysis. The recombinant E. coli BEX （pGEX-PE） cells were collected and sonicated. The supernatants were reserved for the tumor cytotoxic experiments. The result of tumor cytotoxic assay indicated that the supernatants containing PE had the activity of inhibiting the growth of Hela cells and with the increase of protein concentration, the inhibiting rate increased from 37.31% to 63.26%, which showed significant difference from the control. Hydroxyl radical scavenging effect was tested with supernatants of BEX （pGEX-PE） and BGL （pBGL） cell lysates treated with sonication and heating. For the sonication samples, the scavenging rates of the supernatants of BEX （pGEX-PE） and BGL （pBGL） cell lysates were significantly higher than the negative control BL2 I（pGEX-4T） （P〈0.02）, and the scavenging rates increased slowly following the increase of the protein content. For the heating samples, except for the 0.2 mgmL^-1 BGL （pBGL） products, the scavenging effects of the supernatants of BEX （pGEX-PE） and BGL （pBGL） cell lysates were stronger than that of negative control BL21（pGEX-4T）. However, the effect intensity was not positively correlated with the increase of the protein concentration. Though a partially decreased hydroxyl radical scavenging activity was led by heating, the biological activity
文摘Gracilaria tenuistipitata varliui Zhang el Xia is cultivated at two different salinities (21, 33) in the laboratory for 4 weeks. The daily growth rate is determined. The total agar yield and fractional agar composition are analyzed. Results show that algae grow faster in low salinity. The total agar yield is higher under high salinity conditions than under low salinity conditions. Among the eight fractions extracted, the yields of cold water extract and 40% ethanol extract are about the highest In low salinities the yields of autoclaved extract and 60% ethanol extract are higher, while the yield of cold water extract is lower relative to high salinities.
