Trisoligo-scaffolding as an alternative approach toward a protocell
The function of a cellular membrane may be viewed as keeping components together that need to be kept together in order to assure the functional integrity of the whole. Artificial compartmentation schemes are conceivable in which the integrity of geometrically defined 3D scaffolds, such as dodecahedra assure the position and proximity of modules arranged on such scaffolds. Mechanical and logical nanodevices, highly ordered 2D-crystals as well as structural and rigid hollow objects were built using DNA. [43]
We used a new generation of trisoligonucleotides to assemble a atomically-precise dodecahedral DNA-scaffold [44] which can be functionalized and is potentially capable to act as a container-molecule. The DNA dodecahedron results from the self-assembly of 20 trisoligonucleotides with an appropriate sequence design. The DNA nanostructure was characterized by atomic force microscopy and electron microscopy, showing a discrete structure of about 20 nm diameter. The DNA structure was resistant to mung bean nuclease indicating the proposed connectivity. Addressability of the nano-structure was achieved by the introduction of trisoligonucleotides with sequence overhangs. These overhangs hybridize with hybrid molecules composed of a complementary sequence tag and modular function such as a dye or a nano-scaled cluster. Up to six positions have been successfully addressed so far, giving reason to believe that scaffolded multimodularity of highly complex assemblies is within the scope of this approach. Conceivable applications for such constructs are widespread and range from the trapping and functionalization of size-matched nanoscale objects to multimodular machinery. Replication of such scaffolds is conceivable by employing the SPREAD-procedure[13] or a microfluidic variant for a chemical copying of connectivity information.[47,48]