聚乙二醇对溶菌酶淀粉样纤维形成的作用

摘要

Objective To investigate amyloid fibrillation and fibrillar cytotoxicity of lysozyme in the presence of polyethylene glycols (PEG) .Methods PEG was mixed with lysozyme prior to incubation at pH 2 .0 and 55 ℃ .The growth curve of lysozyme fibril was monitored by thioflavin T fluorescence ,and morphology of lysozyme aggregates was visualized under transmission electron micros-copy .The cytotoxicity of lysozyme aggregates was evaluated by measuring hemolysis and aggregation of human red blood cells .Re-sults Incubation of lysozyme under the condition of this study resulted in the formation of amyloid fibrils .All the PEGs tested here-in were able to inhibit lysozyme fibrillation ,and alter the morphology lysozyme aggregates .Upon incubation with PEG ,the surface hydrophobicity and cytotoxicity of resultant aggregates of the protein were decreased .Conclusion PEG is able to inhibit amyloid formation of lysozyme ,and decrease cytotoxicity of the resultant aggregates .%目的 探索在聚乙二醇(PEG)存在的条件下,溶菌酶淀粉样纤维化及由此生成的聚集体对细胞的毒性作用.方法 溶菌酶溶液中分别加入不同相对分子质量的PEG,在pH值为2.0、55℃的条件下孵育.采用硫黄素荧光监测溶菌酶淀粉样纤维化,透射电子显微镜观察聚集体形态,以诱导人红细胞聚集和溶血为指标评估溶菌酶聚集体对细胞膜的损害作用.结果 在实验条件下,溶菌酶可形成淀粉样纤维,所有PEG均能够抑制溶菌酶的淀粉样纤维化,改变溶菌酶聚集体的形态,降低聚集体的表面疏水性和聚集体对细胞的损害作用.结论 PEG能够抑制溶菌酶的淀粉样纤维化,并使溶菌酶聚集体的细胞毒性减弱.