Nanostructuring by Deposition of Protein Channels Formed on Carbon Surfaces

Abstract

The unique stability and self-assembling properties of MspA, a channel protein from Mycobacterium smegmatis, were exploited for a simple and straightforward nanostructuring process. Deposition of buffer droplets containing MspA onto highly ordered pyrolitic graphite (HOPG), followed by thermal curing and high vacuum treatment, yielded three distinct lateral nanostructures, depending upon the deposition conditions. The determining experimental parameters were the protein mass deposited and the temperature during and after deposition. The nanostructures were analyzed using high-resolution transmission (TEM) and raster electron microscopy (REM). The program IMAGE (NIH/USA) yielded a quantitative insight into the geometries and the ordering principles of three lateral nanostructures engineered. Whereas phase I consisted of individual proteins, deposited on HOPG, phase II was found to be a nanostructured supramolecular assembly of protein monomers. Phase III, however, featured arrays of distinct nanochannels, ...