期刊
JOURNAL OF PHYSICAL CHEMISTRY B
卷 113, 期 43, 页码 14480-14486出版社
AMER CHEMICAL SOC
DOI: 10.1021/jp905889z
关键词
-
资金
- National Science Foundation [MCB-0615469]
The amyloid-beta (A beta) peptide, the 39 to 43 amino acid peptide that plays a substantial role in Alzheimer's disease, has been shown to interact strongly with lipids both in vitro and in vivo. A beta-lipid interactions have been proposed as a considerable factor in accelerating A beta aggregation through the templating role of membranes in aggregation disorders. Previous work has shown that anionic lipids are able to significantly increase A beta aggregation rate and induce a structural conversion in A beta from a random coil to a beta-structure that is similar to the monomer structure observed in mature fibrils. However, it is unclear if this structural change occurs with the A beta monomer because of direct interactions with the lipids or if the structural change results from protein-protein interactions during oligomerization. We use extensive replica exchange molecular dynamics simulations of an A beta monomer bound to a homogeneous model zwitterionic or anionic lipid bilayer. From these simulations, we do not observe any significant beta-structure formation except for a small, unstable beta-hairpin formed on the anionic dioleylphosphatidylserine bilayer. Further, we see that the Asp23-Lys28 salt bridge that plays a role in beta-hairpin formation is not substantially formed on the bilayer surface and that Lys28 preferentially interacts with lipids when bound to the bilayer. These results suggest that the structural conversion seen in experiments are not due to the ordering of monomeric A beta on the bilayer surface but are a result of protein-protein interactions enhanced by A beta binding to the cell membrane.
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