MIT Postdoc Sees similarities Between DNA, Bridges

Brief

Johannes Kalliauer, a past student at TU Wien and current postdoctoral associate at the MIT Concrete Sustainability Hub, has dedicated his research to finding common ground between the mechanics of bridges and DNA helices. “Forces and moments act on each system, subjecting each to deformations like twisting, stretching, and warping,” says Kalliauer.

Insight

How is DNA like a bridge? This question is not a riddle or logic game, it is a concern of Johannes Kalliauer’s doctoral thesis.

As a student at TU Wien in Austria, Kalliauer was faced with a monumental task: combining approaches from civil engineering and theoretical physics to better understand the forces that act on DNA.

Kalliauer, now a postdoc at the MIT Concrete Sustainability Hub, says he modeled DNA as though it were a beam, using molecular dynamics principles to understand its structural properties.

“The mechanics of very small objects, like DNA helices, and large ones, like bridges, are quite similar. Each may be understood in terms of Newtonian mechanics. Forces and moments act on each system, subjecting each to deformations like twisting, stretching, and warping,” says Kalliauer.

As a 2020 article from TU Wien noted, Kalliauer observed a counterintuitive behavior when examining DNA at an atomic level. Unlike a typical spring which becomes less coiled as it is stretched, DNA was observed to become more wound as its length was increased.

In situations like these where conventional logic appears to break down, Kalliauer relies on the intuition he has gained as an engineer.

“To understand this strange behavior in DNA, I turned to a fundamental approach: I examined what was the same about DNA and macroscopic structures and what was different. Civil engineers use methods and calculations which have been developed over centuries and which are very similar to the ones I employed for my thesis,” Kalliauer explains.