Degradation, Deproteinization And Bioactivity Of Abalone Proteo-polysaccharides

The polysaccharide-protein complexes isolated from abalone gonad demonstrated multiple bioactivities. In this study, the complexes were degraded into oligosacchardes by were prepared by diluted acid; On the other hand, the complexes were deproteinized by P-elimination method to prepare series products with different content of protein. The bioactivities of the oligosaccharides and deproteinized products were investigated to elucidate the structure-activity relationship and thus to provide new basis for developing new products made from abalone gonads. The aim of this work is to investigate the relationships between the protein content and the biological activities in glycoconjugates.First, β-elimination method, together with Sevag treatment was used to eleminate the protein in the complexes, and five fractions were obtained. Results showed that, as the β-elimination reaction time rose from 0 h to 72 h, the protein contents of the producs were gradually reduced and reached an minimum level by 72 h treatment. The chromatography and FT-IR spectrum of the products demonstrated that β-elimination reaction didn’t significantly change molecular size, structure and component.The effect of the deproteinized products on a series bioactivities, such as lymphocyte proliferation activity, classical pathway complement activity, protection of tBOOH-induced oxidative stress assay and inhibition on Hela cell proliferation in vitro, were investigated. Result indicated that both the original complexes and deproteinized products could stimulate lymphocyte proliferation, but the activity was weakened with the lower of the protein content. The data showed that the inhibition effect of the deproteinized products on complement activation was significantly increased at a concentration of 0.5 mg/mL and 0.1 mg/mL, respectively. The protective effect of result of the 72 h deproteinized products on tBOOH induced oxidative stress significantly decreased at a concentration of 0.5 mg/mL and 0.1 mg/mL. Inhibitory activity of 72 h deproteinized products on proliferation of Hela cells increased to 2 folds of that of the original complexes.Second, the complexes was degraded by diluted acid, and a series oligosaccharides with different molecular weight was prepared by controlling the reaction temperature and time. The molecular weights and their distributions were measured by High Performance Liquid Chromatography (HPLC), Column Chromatography and Viscosity Measured methods. Results showed that the molecular weight lowered rapidly and tended to stable after 2 h reaction. FT-IR spectrum exhibited that The sulfated functional groups have been broken and a large number of hydroxyl groups were newly generated.The effect of the degraded products on a series bioactivities, such as lymphocyte proliferation activity, classical pathway complement activity, RAW 264.7 cell proliferation, NO production level, protection of tBOOH-induced oxidative stress assay and inhibition on Hela cell proliferation in vitro, were investigated. Significant changes were observed after degradation, and a inflection point occured at 1 h or 1.5 h for the change of bioactivities. It suggested that the change of molecular weight and sulfated functional groups had a direct influence on biological activities. When degradation time was extended longer than 1.5 h, the biological activities increased a bit, which might relevant with the newly generated hydroxyl groups.