Publication: Self-assembly of the ionic peptide EAK16: The effect of charge distributions on self-assembly
All || By Area || By YearTitle | Self-assembly of the ionic peptide EAK16: The effect of charge distributions on self-assembly | Authors/Editors* | Jun S, Hong Y, Imamura H, Ha BY, Bechhoefer J, Chen P |
---|---|
Where published* | BIOPHYSICAL JOURNAL |
How published* | None |
Year* | 2004 |
Volume | 87 |
Number | 0 |
Pages | 1249-1259 |
Publisher | BIOPHYSICAL SOCIETY |
Keywords | MOLECULAR-DYNAMICS SIMULATIONS; HISTOGRAM ANALYSIS METHOD; FREE-ENERGY CALCULATIONS; ATOMIC-FORCE MICROSCOPY; COMPLEMENTARY OLIGOPEPTIDE; BIOLOGICAL-MATERIALS; UNFOLDED PROTEINS; FOLDING PATHWAYS; AMYLOID FIBRILS; AGGREGATION |
Link | |
Abstract |
Amphiphilic peptides suspended in aqueous solution display a rich set of aggregation behavior. Molecular-level studies of relatively simple amphiphilic molecules under controlled conditions are an essential step toward a better understanding of self-assembly phenomena of naturally occurring peptides/proteins. Here, we study the influence of molecular architecture and interactions on the self-assembly of model peptides (EAK16s), using both experimental and theoretical approaches. Three different types of EAK16 were studied: EAK16-I, -II, and -IV, which have the same amino acid composition but different amino acid sequences. Atomic force microscopy confirms that EAK16-I and -II form fibrillar assemblies, whereas EAK16-IV forms globular structures. The Fourier transform infrared spectrum of EAK16-IV indicates the possible formation of a beta-turn structure, which is not found in EAK16-I and -II. Our theoretical and numerical studies suggest the underlying mechanism behind these observations. We show that the hairpin structure is energetically stable for EAK16-IV, whereas the chain entropy of EAK16-I and -II favors relatively stretched conformations. Our combined experimental and theoretical approaches provide a clear picture of the interplay between single-chain properties, as determined by peptide sequences ( or charge distributions), and the emerging structure at the nano ( or more coarse-grained) level. |
Back to page 101 of list