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利用ThT荧光分析法、透射电子显微镜和圆二色光谱检测αs1-酪蛋白形成淀粉样纤维沉淀(Fibril)的动力学过程,优化了其形成条件,研究了Fibril形成的影响因素.实验结果表明,αs1-酪蛋白在65℃高温下,pH=5～5.4的范围内,加热144 h以上,可以形成Fibril.在此过程中,αs1-酪蛋白的二级结构由α螺旋构象向β折叠构象转变.甘油磷酸胆碱D6PC可以显著地促进αs1-酪蛋白Fibril的形成,并呈浓度依赖性,说明一定条件下蛋白质可能与细胞膜的磷脂之间存在相互作用,从而导致酪蛋白二级构象的转变.硫酸肝素对αs1-酪蛋白形成Fibril无影响,说明硫酸肝素对蛋白质二级构象的影响作用因蛋白质的不同而不同,与不同蛋白质的Fibril形成机制相关.
The kinetics of αs1-casein formation by amyloid fibroin deposition (Fibril) was measured by ThT fluorescence analysis, transmission electron microscopy and circular dichroism spectroscopy, and the formation conditions of Fibril were optimized, and the influencing factors of Fibril formation were studied.Experimental results show that, The αs1-casein can form Fibril by heating for more than 144 h at a high temperature of 65 ° C and a pH of 5 to 5.4 In the process, the secondary structure of αs1-casein changes from α-helical conformation to β-sheet conformation Glycerophosphocholine D6PC can significantly promote the formation of αs1-casein Fibril in a concentration-dependent manner, indicating that the protein may interact with the phospholipid of cell membrane under certain conditions, resulting in the change of casein secondary conformation. Heparin sulfate had no effect on the formation of Fibril by αs1-casein, indicating that the effect of heparin sulfate on the secondary conformation of the protein varies with different proteins and is related to the Fibril formation mechanism of different proteins.