PROTEIN-DNA DOUBLE AND TRIPLE LAYERS - INTERACTION OF BIOTINYLATED DNA FRAGMENTS WITH SOLID SUPPORTED STREPTAVIDIN LAYERS

The specific interaction of streptavidin with biotinylated lipids at t he air-water interface leads to a formation of optically anisotropic t wo-dimensional streptavidin (2-D) crystals, where two of the original four biotin-binding sites remain free. These assembled streptavidin ma trixes were used as a template for docking of double-stranded oligonuc leotides biotinylated at a terminal or a centered position. A biotinyl ated lipid monolayer was deposited on an electrode of a quartz crystal microbalance (QCM), and docking processes of the protein and the olig onucleotides were detected as frequency changes related by mass change s on the QCM. The bis-biotinylated double-stranded oligonucleotides bo und to the primary streptavidin layers made it possible to engineer pr otein-DNA-protein triple layers. Hydrolysis by a restriction endonucle ase indicates that the biotinylated DNA bound to the streptavidin laye rs remains bioactive.