Journal of Physical Chemistry B, Vol.114, No.1, 620-625, 2010
Time-Lapse Atomic Force Microscopy Observations of the Morphology, Growth Rate, and Spontaneous Alignment of Nanofibers Containing a Peptide-Amphiphile from the Hepatitis G Virus (NS3 Protein)
Time-lapse atomic force microscopy is used ill this contribution to directly watch the growth of nanofibers of a lipidated peptide oil a mica Surface. Specifically, the Studied lipopeptide is the palmitoyl derivative of the fragment 505-514 of NS3 protein from the hepatitis G Virus, abbreviated as Palmitoyl-NS3 (505-514). Data on the morphology, growth rate, and orientation of these peptide-amphiphile nanofibers have been obtained. From these data, it call be concluded that this synthetic lipopeptide forms two types of fiber-like aggregates: (i) half-spherical fibrous aggregates with lengths of hundreds of nanometers and (ii) spherical fibrous aggregates with lengths of Several micrometers. In addition, when a fresh lipopeptide aqueous solution is deposited onto a mica surface, the aggregates Spontaneously orient parallel to each other, yielding well-aligned nanofibers oil large areas of the mica surface. A significant growth in both the length and the number of the fibers was observed during the first Minutes after the Solution deposition. Elongation of the fibrous aggregates from one end is more frequent, though elongation from both ends also Occurs, with growth rates in the 4-5 nm/s range. The effects of dilution, mechanical perturbation, and pH oil the aggregation behavior of Palmitoyl-NS3 (505-514) are also detailed in this paper.