Engineers build DNA ‘nanotowers’ with enzyme tools

October 13, 2005 | Source: KurzweilAI

Duke engineers are creating the tools that will make bio-manufacturing possible at an industrial scale.

“The development of bio-nanotechnological tools and fabrication strategies, as demonstrated here, will ultimately allow the automated study of biology at the molecular scale and will drive our discovery and understanding of the basic molecular machinery that defines life,” said Stefan Zauscher, assistant professor of mechanical engineering and materials science.

They can vertically extend short DNA chains attached to nanometer-sized gold plates, using an enzyme called TdTase. The team starts with a forest of short DNA strands that cover nanoscale patches of gold, lithographed onto a silicon substrate. The researchers then submerge the substrate in a solution that contains the TdTase (terminal deoxynucleotidyl transferase) enzyme, a cobalt catalyst and the molecular building blocks, called nucleotides, of DNA chains.

Over an hour, the TdTase enzyme grabs the free-floating nucleotides and builds nanoscale “towers” above the surface by extending each DNA strand, increasing its height a hundredfold. In addition, the process works at room temperature in an incubator that maintains humidity.

Ashutosh Chilkoti, associate professor of biomedical engineering at Duke’s Pratt School of Engineering, said the next step towards bio-nanofabrication is to create a little crane to pick up, move and place biological molecules in precise locations on three-dimensional DNA surfaces.

“When we can place molecules in the right configuration, then we can get them to function. At that point, we can design and create biological machines that accomplish something,”