Journal of Physical Chemistry B, Vol.112, No.30, 8950-8954, 2008
Parallel-oriented fibrogenesis of a beta-sheet forming peptide on supported lipid bilayers
Peptide self-assembly on substrates is currently an intensively studied topic that provides a promising strategy for fabrication of soft materials and is also important for revealing the surface chemistry of amyloidogenic proteins that aggregate on cell membranes. We investigated the fibrogenesis of a beta-sheet forming peptide A beta(26-35) on supported lipid bilayers (SLBs) by in situ atomic force microscopy (AFM), circular dichroism (CD), and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The results show that the A beta(26-35) nanofilaments' growth is oriented to a specific direction and formed a highly ordered, large-scale, parallel-oriented surface pattern on membranes. The parallel-oriented fibrogenesis of A beta(26-35) was able to occur on different lipid membranes rather than on solid substrates. It implies that the parallel-oriented fibrogenesis was associated with the distinct properties of lipid membranes, such as the fluid nature of lipid molecules on membranes. The membrane fluidity may allow the peptide assemblies to float at the water-membrane interface and easily orient to an energetically favorable state. These results provide an insight into the surface chemistry of peptide self-assembly on lipid membranes and highlight a possible way to fabricate supramolecular architectures on the surface of soft materials.