| AVS 54th International Symposium | |
| Biomaterial Interfaces | Tuesday Sessions |
| Session BI-TuP |
| Session: | Biomaterials Interfaces Poster Session |
| Presenter: | M.A. Bratescu, Nagoya University, Japan |
| Authors: | M.A. Bratescu, Nagoya University, Japan D.B. Allred, Nagoya University, Japan, and University of Washington N. Saito, Nagoya University, Japan M. Sarikaya, University of Washington O. Takai, Nagoya University, Japan |
| Correspondent: | Click to Email |
Surface-layer (S-layer) proteins from many species of bacteria and archaea self-assemble into two-dimensional supramolecular arrays and form specific space groups. Although S-layer proteins are now used as molecular and nanoscale templates for nano- and bio-nanotechnology, the fundamental bases of assembly and ordered organization are still under study. The purpose of our research is to characterize adsorption specificity, surface interactions, and assembly of S-layer proteins on solid surfaces. We use absorption of UV evanescent light produced by multiple total internal reflections in a quartz IRE sensor which is sensitive to a depth of a few tens of nanometers. The S-layer proteins were prepared as described in Ref. [1], starting from a cell culture of Deinococcus radiodurans. A final concentration of protein in sodium dodecyl sulfate was estimated to be 0.5 mg mL -1. For experiments, the protein solution was diluted in deionized water to a concentration of 0.2 mg mL -1. A comparative analysis of the S-layer protein adsorption was performed on different functionalized surfaces (amino- and hydroxyl- terminated) or surfaces deposited with noble metals (platinum and gold). The amino-terminated monolayer was obtained by dipping freshly cleaned quartz into a 1 wt % solution of (3-aminopropyl) trimethoxysilane in toluene for 3 hours at 60 ° C. The hydroxyl-terminated surface was obtained by photochemical exposure of quartz to VUV radiation at 172 nm. The noble metals were deposited by magnetron sputtering. S-layer protein absorption bands were found at 274 nm and 307 nm, characteristic of tryptophan and tyrosine residues, which have UV absorption bands in the spectral region 270 - 350 nm. The strongest absorption was obtained when S-layer proteins were adsorbed on an amino-terminated surface. Time dependence of protein adsorption will be correlated with data obtained by atomic force microscopy analysis of S-layer proteins on different solid surfaces to derive a better understanding of the adsorption process.
1D.B. Allred, M. Sarikaya, F. Baneyx, D.T. Schwartz, Nano Lett., 5 (2005) 609.