期刊
PROTEIN ENGINEERING DESIGN & SELECTION
卷 22, 期 12, 页码 741-746出版社
OXFORD UNIV PRESS
DOI: 10.1093/protein/gzp059
关键词
A-beta; amyloid formation; Couette flow; rate; stirring
资金
- Australian Research Council [LP0562318]
- Australian Research Council [LP0562318] Funding Source: Australian Research Council
The rate of formation of amyloid fibrils in an aqueous solution of amyloid-beta (A beta) is greatly increased when the solution is sheared. When A beta solution is stirred with a magnetic stirrer bar at 37 degrees C, a rapid increase in thioflavin T fluorescence is observed. Atomic Force Microscopy (AFM) images show the formation of aggregates, the growth of fibrils and the intertwining of the fibrils with time. Circular dichroism (CD) spectroscopy of samples taken after stirring shows a transition from random coil to alpha-helix to beta-sheet secondary structure over 20 h at 37 degrees C. The fluorescence, AFM and CD measurements are all consistent with the formation of amyloid fibrils. Quiescent, non-stirred solutions incubated at 37 degrees C showed no evidence of amyloid formation over a period of 3 days. Couette flow was found to accelerate the formation of amyloid fibrils demonstrating that the primary effect of stirring is not mixing but shearing. Only very small shear forces are applied to individual molecules in our experiments. Simple calculation suggests that the force is too small to support a hypothesis that shearing promotes partial unfolding of the protein as is observed.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据