Scientists 'Weave' DNA Networks Using Two Types of Molecular Machines

Researchers led by Institute of Science Tokyo and Kyoto University have built a system that grows DNA-based network materials from the bottom up, using two types of biomolecular machines working in sequence — a step the team says mimics how living cells coordinate multiple processes to build ordered structures. The findings were published in the journal Small.

The team, led by assistant professor Shogo Hamada and co-led by professor Akira Kakugo, combined DNA polymerase, an enzyme that copies and extends DNA strands, with kinesin, a motor protein that moves along microtubules by consuming a fuel molecule called ATP. First, DNA polymerase amplified DNA templates attached to microtubules, growing long DNA strands directly on them. Kinesin motors fixed to a surface then propelled these DNA-carrying microtubules across it.

When the gliding microtubules collided, the DNA strands riding on them connected, and as the microtubules kept moving, they mechanically stretched and pulled the joined strands into a growing network of fiberlike structures. No networks formed when kinesin was absent or when ATP was depleted, confirming that motor activity drives the process. Increasing microtubule density and DNA synthesis time produced networks with higher connectivity and complexity, and simulations of the chains reproduced the same architectures seen in the lab.

"By coupling molecular synthesis with mechanical force generation, we have taken a crucial step toward creating synthetic materials that mimic the dynamic construction strategies of living systems," Hamada said. The researchers said the framework could eventually lead toward programmable, lifelike materials with self-repairing and self-sustaining properties, with potential applications including molecular computing and molecular robotics.