超过20种人类疾病与蛋白质或者多肽淀粉样纤维化密切相关,探究影响蛋白质的结构稳定性及其淀粉样纤维化的环境条件具有重要意义.本文采用牛胰岛素作为模型蛋白质,研究了Na2SO4对蛋白质淀粉样纤维化的作用.实验结果表明,不同浓度的Na2SO4对胰岛素淀粉样纤维化过程具有不同的影响,低浓度条件下可促进纤维化,较高浓度可明显抑制淀粉样纤维的形成,更高的浓度则使胰岛素形成非纤维状聚集体.ANS荧光分析结果表明,所有浓度的Na2SO4均可减小胰岛素聚集体的表面疏水性,并导致聚集体对细胞膜的损害作用降低.Na2SO4的上述作用可能与其改变蛋白质分子间的静电作用力及溶剂效应有关.%Amyloid fibrillation of protein or peptide was associated with more than 20 human diseases. It was of significance to explore the physical and chemical circumstances under which the fibrillation of a protein is triggering and proceeding. In the present study,the effects of sodium sulfate on the amyloid fibrillation and the fibnllar cytotoxicity of bovine insulin had been investigated. The results demonstrated that sodium sulfate played varied roles on insulin fibrillation, depending on the concentration of the salt applied. Low concentration of sodium sulfate enhanced the fibril fonnation, whereas high concentration of the salt resulted in an inhibition of the fibrillation or the formation of non-fibrillar aggregates. ANS assay showed that sodium sulfate decreased the fibnllar surface hydrophobicity and consequently the fibril-induced membrane damages were attenuated,as demonstrated by SDS-PAGE. The alterations in solvation and electrostatic force were possibly involved in the multiple effects of sodium sulfate on the amyloidogenesis of insulin.
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