Purification And Bioactivities Of Polysaccharide Conjugates From Scallop Gonad

Polysaccharide conjugates were extracted and purified from scallop gonad, and their bioactivites, such as antioxidant, anti-tumor, anticogulation and immunomodulating activities were investigated in vitro.First, crude scallop gonad polysaccharide (CSGP) was obtained from scallop gonad by protease hydrolysis followed by ethanol precipitation. CSGP was purified by DEAE-52 anion exchange chromatography, and 3 polysaccharide fractions, named SGP1, SGP2 and SGP3 were obtained. The molecular masses of SGP2 and SGP3 were evaluated to be 270 kDa and 80 kDa by Sepharose CL-6B gel filtration chromatography. CSGP was demonstrated to have reducing power with abilities to scavenge DPPH free radicals and hydroxyl free radicals. The protective abilities of CSGP, SGP2, and SGP3 on tBOOH-induced cell oxidative damage were investigated and the results showed that CSGP could not directly protect the damaged cells, but could indirectly protect the cells at concentrations of 0.2,1 and 5 ug/mL. SGP3 showed both direct and indirect protective effect, but SGP2 could only indirectly protect the cells at lower concentration (0.2 μg/mL). Other experimental results indicated that, CSGP, SGP2, and SGP3 could stimulate lymphocyte proliferation at concentrations of 0.2,1 and 5 μg/mL, and the activity of SPG2 was the most significant. CSGP, SGP2, and SGP3 could also inhibite the classic complement activity at concentrations of 1,10,50 and 100 μg/mL, and the activity of SGP3 was the most significant. The anticoagulating experiments for CSGP and SGP3 could prolong APTT and TT at concentrations of 5,20 and 40 μg/mL, but SGP2 could not. CSGP, SGP2, and SGP3 did not exhibit cytotoxicity on Hela cell.Second, crude scallop gonad glycoprotein (CSGG) was prepared from scallop gonad by Triton followed by ethanol precipitation. CSGG was purified by DEAE-52 anion exchange chromatography, and three glycoprotein fractions, named SGG1, SGG2 and SGG3 were obtained. SGG2 was hydrolysed by trypsin, and the hydrolysate was purified by Sepharose CL-6B, producing three fractions with different molecular weight, SGG2-1, SGG2-2, SGG2-3. CSGG was demonstrated to have reducing power with abilities to scavenge DPPH free radicals and hydroxyl free radicals. SGG2-2 demonstrated stronger effect than SGG2-1...