Autonomous loading, transport, and unloading of specified cargoes by using DNA hybridization and biological motor-based motility

A molecular transport system that can achieve autonomous loading/unloading of specified cargoes using DNA hybridization was investigated. The chemical linkages to label micro tubules (MTs) with ssDNAs was examined. The 23-mer spacer was introduced to prevent collapse of ssDNAs onto the MT surface and to keep the single-stranded sticky end free. The base sequence used in the sticky end regions were designed so that they were expected to have the same melting temperature and to rapidly hybridize at room temperature. The C-23c cargo was occasionally loaded onto the gliding MT-10 filament. Three types of MTs with different lengths of single-stranded sticky ends were prepared to confirm that the observed loading of cargoes onto gliding MRs was caused by selective DNA hybridization. Biotinylated DNAs with a 23-mer double-stranded spacer and a 23-mer single-stranded sticky end were immobilized onto a glass substrate through streptavidin-biotin linkages together with biotinylated kinesins.