Hirota-Nakaoka Nami, Hasegawa Kazuhiro, Naiki Hironobu, Goto Yuji
Institute for Protein Research, Osaka University and CREST, Japan Science and Technology Corporation, Suita, Osaka 565-0871.
J Biochem. 2003 Jul;134(1):159-64. doi: 10.1093/jb/mvg124.
Increasing numbers of proteins have been found to aggregate into insoluble fibers, collectively referred to as amyloid fibrils. To address the conformational stability of amyloid fibrils, we studied the effects of dimethylsulfoxide (DMSO), 2,2,2-trifluoroethanol (TFE), and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) on beta(2)-microglobulin amyloid fibrils by circular dichroism, thioflavin T fluorescence, light scattering, and electron microscopy. When measured by circular dichroism and thioflavin T fluorescence, HFIP, and TFE dissolved the fibrils, producing predominantly helical conformations. However, these alcohols did not dissolve the amyloid fibrils completely as monitored by light scattering and electron microscopy. On the other hand, DMSO completely dissolved the amyloid fibrils although a high concentration [i.e., 80% (v/v)] was required. These results are consistent with the important role of hydrogen bonds in stabilizing amyloid fibrils.
越来越多的蛋白质被发现会聚集成不溶性纤维，统称为淀粉样纤维。为了研究淀粉样纤维的构象稳定性，我们通过圆二色性、硫黄素T荧光、光散射和电子显微镜研究了二甲基亚砜（DMSO）、2,2,2-三氟乙醇（TFE）和1,1,1,3,3,3-六氟-2-丙醇（HFIP）对β2-微球蛋白淀粉样纤维的影响。通过圆二色性和硫黄素T荧光测量时，HFIP和TFE溶解了纤维，主要产生螺旋构象。然而，通过光散射和电子显微镜监测，这些醇并没有完全溶解淀粉样纤维。另一方面，尽管需要高浓度[即80%（v/v）]，DMSO完全溶解了淀粉样纤维。这些结果与氢键在稳定淀粉样纤维中的重要作用一致。
