作者：何乃普*;潘素娟;王榮民
關(guān)鍵字：熱誘導(dǎo), 蛋白質(zhì), 殼聚糖, 自組裝, 機(jī)理
論文來源：期刊
具體來源：http://www.gfzxb.org/CN/abstract/abstract14405.shtml
發(fā)表時間：2016年
80 ℃熱誘導(dǎo)牛血清白蛋白(BSA)變性,BSA疏水殘基暴露在分子表面,并進(jìn)一步凝膠化.采用紫外-可見光光度儀(UV-Vis)和動態(tài)激光光散射儀(DLS)考察了熱處理時間、溶液pH值、殼聚糖(CS)與BSA配比等因素對CS與BSA自組裝行為的影響.加熱時間介于15~20 min,BSA與CS發(fā)生自組裝;BSA/CS混合體系pH大于BSA等電點(diǎn)(pI=4.7)時,BSA與殼聚糖靜電作用增強(qiáng),隨著pH增大,出現(xiàn)沉淀.BSA濃度過高,變性BSA之間聚集作用增強(qiáng),導(dǎo)致體系出現(xiàn)沉淀.研究結(jié)果顯示,CS阻礙了BSA自身凝膠化進(jìn)程,并與BSA發(fā)生自組裝.在pH=5.4的溶液中制備了BSA-CS自組裝體.采用透射電鏡(TEM)觀察了自組裝體的形態(tài),采用DLS對其粒徑及其分布進(jìn)行了測試.自組裝體是以BSA聚集體為核、CS分子鏈為殼的核殼納米結(jié)構(gòu).制備的自組裝體室溫貯存40天后,其粒徑和分布無明顯變化.
The unfolding of bovine serum albumin (BSA) was induced by heating at 80 ℃,and hydrophobic residues were exposed on the BSA surface,which caused the gelation of BSA.Influences of heating temperature and time,pH value and the ratio of BSA to chitosan on the self-assembly behavior between denatured BSA and chitosan (CS) in aqueous solutions were explored by the ultraviolet-visible spectroscopy (UV-Vis) and dynamic light scatter (DLS).The self-assembly behavior of BSA and chitosan occurred at 80 ℃ for 15-20 min.At pH> 4.7(the isoelectric point of BSA,pI=4.7),electrostatic interactions between BSA and chitosan enhanced,and as pH is increased,precipitates were formed in the mixture system.At high concentrations of BSA,aggregation of denatured BSA resulted in precipitation of the aggregates.The results indicated that chitosan hindered the gelation process of BSA and self-assembled with denatured BSA by heating at 80 ℃.BSA-CS self-assemblies were fabricated at pH 5.4 in aqueous solutions by heating at 80 ℃.The morphology of nanoparticles was observed by the transmission electron microscopy (TEM) and the size and it distribution were measured by DLS.BSA-CS self-assemblies were constituted by the core consisting of BSA aggregates and the shell consisting of chitosan chains.Self-assemblies were stored without any changes at room temperature for 40 days.