Salts drive controllable multilayered upright assembly of amyloid-like peptides at mica/water interface
Salts drive controllable multilayered upright assembly of amyloid-like peptides at mica/water interface
复制标题
盐驱动云母/水界面处类淀粉样肽的可控多层垂直组装
DOI：
10.1073/pnas.1220711110
复制
发表时间：
2013-05-21
影响因子：
11.1
通讯作者：
Zhou, Ruhong
中科院分区：
文献类型：
--
作者：
Dai, Bin;Kang, Seung-gu;Zhou, Ruhong
Surface-assisted self-assembly of amyloid-like peptides has received considerable interest in both amyloidosis research and nanotechnology in recent years. Despite extensive studies, some controlling factors, such as salts, are still not well understood, even though it is known that some salts can promote peptide self-assemblies through the so-called "salting-out" effect. However, they are usually noncontrollable, disordered, amorphous aggregates. Here, we show via a combined experimental and theoretical approach that a conserved consensus peptide NH2-VGGAVVAGV-CONH2 (GAV-9) (from representative amyloidogenic proteins) can self-assemble into highly ordered, multilayered nanofilaments, with surprising all-upright conformations, under high-salt concentrations. Our atomic force microscopy images also demonstrate that the vertical stacking of multiple layers is highly controllable by tuning the ionic strength, such as from 0 mM (monolayer) to 100 mM (mainly double layer), and to 250 mM MgCl2 (double, triple, quadruple, and quintuple layers). Our atomistic molecular dynamics simulations then reveal that these individual layers have very different internal nanostructures, with parallel beta-sheets in the first monolayer but antiparallel beta-sheets in the subsequent upper layers due to their different microenvironment. Further studies show that the growth of multilayered, all-upright nanostructures is a common phenomenon for GAV-9 at the mica/water interface, under a variety of salt types and a wide range of salt concentrations.
