Isolation and Study of S-layer Nanostructure of Deinococcus Radiodurans R1

Crystalline surface layer proteins (S-layer proteins) have considerable potential for the crystalline arrays in biotechnology, biomimetics and nonlife applications, including areas such as microelectronics and molecular nanotechnology. The extensive application potential of surface layers in nanobiotechnology is according to the particular inherent attributes of the single molecular arrays consisted of uniform protein or glycoprotein subunits. Most important, functional groups on the protein lattice are arrayed in well-specified positions and orientations. Many applications of S-layers are related to the ability of isolated subunits to recrystallize into single molecular arrays in suspension, suitable surfaces or interfaces. Utilization of the s-layers as template to pattern inorganic nanostructures, requires the separation and purification of these proteins and study of their structures on solid surfaces. The hexagonally packed intermediate (Hpi) protein of Deinococcus radiodurans belongs to the category of S-layer proteins which form crystalline two-dimensional arrays on bacterial cell surfaces. In this study, Deinococcus radiodurans R1 S-layer was purified and SDS-PAGE of purified HPI layer was analyzed by Core Laboratory Image Quantification Software. And also, secondary structure of Isolated HPI layer was evaluated by Circular Dichroism. and Zeta potential measurement was carried out to define surface charge of HPI surface layer sheets. In addition, hexagonally pattern of HPI sheets have been studied by atomic force microscopy and field emission scanning electron microscopy. According to our results, isolated HPI layer from Deinococcus radiodurans R1 can be used as template to array nanoparticles in future works.