i-Motif is formed from two parallel duplexes by intercalating with each other in an antiparallel orientation and each duplex is held together-via-hemiprotonated cytosine+-cytosine base pairs.However,a cell is crowded ...i-Motif is formed from two parallel duplexes by intercalating with each other in an antiparallel orientation and each duplex is held together-via-hemiprotonated cytosine+-cytosine base pairs.However,a cell is crowded with various biomolecules and little is known about the properties of i-Motif under molecular crowding conditions until now.In the present study,we used human telomeric DNA sequence,[C3TA23C3,as a model system to investigate such problem by circular dichroism(CD) and UV absorbance spectroscopy.Based on the CD spectra,we found that there were no changes about the structure of i-Motif in the presence of polyethylene glycol(PEG).CD melting results showed that the thermal stability of i-Motif was increased under molecular crowding conditions compare to that in dilute buffer,which was further demonstrated by UV-melting results.This work suggests that molecular crowding could not affect the structure of i-Motif,which may depend on pH,while could enhance the thermal stability of i-Motif.展开更多
采用胃蛋白酶适度水解大豆分离蛋白得到蛋白肽,在大分子拥挤环境下通过Maillard反应制备蛋白肽-葡聚糖共价复合物(Hydrolated Soy Protein Isolated-Dextran Conjugates,HDC),采用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)技术证实...采用胃蛋白酶适度水解大豆分离蛋白得到蛋白肽,在大分子拥挤环境下通过Maillard反应制备蛋白肽-葡聚糖共价复合物(Hydrolated Soy Protein Isolated-Dextran Conjugates,HDC),采用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)技术证实大豆7S球蛋白和葡聚糖发生了共价结合,并通过乳化剪切机、荧光分光光度计、差示扫描量热仪和粒度分布仪等对其接枝度、溶解性、热稳定性、抗氧化性和乳化性能进行系统分析。结果表明:大分子拥挤环境下大豆水解蛋白肽-葡聚糖60℃反应4 h就可以形成较高接枝度的共价复合物,溶解性较大豆分离蛋白(Soybean protein isolated,SPI)和大豆分离蛋白-葡聚糖(Soybean Protein Isolated-Dextran Conjugates,SDC)有所提高,热稳定性好,HDC的自由基清除率明显高于大豆水解蛋白和它与葡聚糖的混合物,达到66.39%,且羟自由基清除率高于维生素C,HDC的乳液粒径最小并具有优越的乳化稳定性。展开更多
文摘i-Motif is formed from two parallel duplexes by intercalating with each other in an antiparallel orientation and each duplex is held together-via-hemiprotonated cytosine+-cytosine base pairs.However,a cell is crowded with various biomolecules and little is known about the properties of i-Motif under molecular crowding conditions until now.In the present study,we used human telomeric DNA sequence,[C3TA23C3,as a model system to investigate such problem by circular dichroism(CD) and UV absorbance spectroscopy.Based on the CD spectra,we found that there were no changes about the structure of i-Motif in the presence of polyethylene glycol(PEG).CD melting results showed that the thermal stability of i-Motif was increased under molecular crowding conditions compare to that in dilute buffer,which was further demonstrated by UV-melting results.This work suggests that molecular crowding could not affect the structure of i-Motif,which may depend on pH,while could enhance the thermal stability of i-Motif.
文摘采用胃蛋白酶适度水解大豆分离蛋白得到蛋白肽,在大分子拥挤环境下通过Maillard反应制备蛋白肽-葡聚糖共价复合物(Hydrolated Soy Protein Isolated-Dextran Conjugates,HDC),采用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)技术证实大豆7S球蛋白和葡聚糖发生了共价结合,并通过乳化剪切机、荧光分光光度计、差示扫描量热仪和粒度分布仪等对其接枝度、溶解性、热稳定性、抗氧化性和乳化性能进行系统分析。结果表明:大分子拥挤环境下大豆水解蛋白肽-葡聚糖60℃反应4 h就可以形成较高接枝度的共价复合物,溶解性较大豆分离蛋白(Soybean protein isolated,SPI)和大豆分离蛋白-葡聚糖(Soybean Protein Isolated-Dextran Conjugates,SDC)有所提高,热稳定性好,HDC的自由基清除率明显高于大豆水解蛋白和它与葡聚糖的混合物,达到66.39%,且羟自由基清除率高于维生素C,HDC的乳液粒径最小并具有优越的乳化稳定性。
