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80℃热诱导牛血清白蛋白(BSA)变性,BSA疏水残基暴露在分子表面,并进一步凝胶化.采用紫外-可见光光度仪(UV-Vis)和动态激光光散射仪(DLS)考察了热处理时间、溶液p H值、壳聚糖(CS)与BSA配比等因素对CS与BSA自组装行为的影响.加热时间介于15~20 min,BSA与CS发生自组装;BSA/CS混合体系p H大于BSA等电点(p I=4.7)时,BSA与壳聚糖静电作用增强,随着p H增大,出现沉淀.BSA浓度过高,变性BSA之间聚集作用增强,导致体系出现沉淀.研究结果显示,CS阻碍了BSA自身凝胶化进程,并与BSA发生自组装.在p H=5.4的溶液中制备了BSA-CS自组装体.采用透射电镜(TEM)观察了自组装体的形态,采用DLS对其粒径及其分布进行了测试.自组装体是以BSA聚集体为核、CS分子链为壳的核壳纳米结构.制备的自组装体室温贮存40天后,其粒径和分布无明显变化.
Bovine serum albumin (BSA) was denatured by heat at 80 ℃, BSA hydrophobic residues were exposed on the surface of the molecule and further gelatinized.Using UV-Vis and DLS, Heat treatment time, solution pH value, the ratio of chitosan (CS) and BSA on the self-assembly behavior of CS and BSA.The self-assembly of BSA and CS occurred when the heating time ranged from 15 to 20 min, and the BSA / CS mixture The electrostatic interaction between BSA and chitosan was enhanced when p H was larger than the isoelectric point of BSA (p I = 4.7), with the increase of p H, precipitation was observed.As the concentration of BSA was too high, the aggregation between denatured BSA increased, The results show that CS block the self-gelation of BSA and self-assemble with BSA.The self-assembly of BSA-CS was prepared in a solution of p H = 5.4.The TEM The particle size and its distribution were tested by DLS.The self-assembly was a core-shell nanostructure with BSA aggregates as core and CS molecular chain as shell.The prepared self-assembly was stored for 40 days at room temperature, No significant change in particle size and distribution.