Spotlight on the Machinery of Life

18.08.2017, 10:10

Physicists in Erlangen have succeeded in recording molecular movement using nothing but light

Molecules attach to gold atoms. Because the reaction is visible in the sensor signal, the plasmonic nanosensor can be used to rapidly optimize surface reactions.


A research group at the Max Planck Institute for the Science of Light in Erlangen has developed a nanosensor for observing enzymes and other biomolecules as they function in real time. With this sensor, they have for the first time tracked the movement of the enzyme polymerase, which produces the genetic material DNA, using nothing but light. The new method can also be used to study the way enzymes work, which could help identify new approaches to medicinal substances. 

The research team led by Frank Vollmer, who is in charge of a team at the Max Planck Institute for the Science of Light until the end of the year, developed a method by which they can observe enzymes without dye markers, simply using light. The group published its results in the journals Science and Nature. 

The microscopic sensor developed by the Erlangen scientists is built of two components: A gold nanofilament, about 40 nanometers in length, sits on a small glass bead and generates a light spot. If an enzyme or molecule binds to the gold filament, it is bathed in the light spot. A sensor records the signals of these enzyme movements. 

In one of their experiments, the physicists attached the enzyme DNA polymerase to their sensor and recorded its movement. They were able to track the way the enzyme opened and closed in real time. “If our methods are developed further, we could even record the production of a strand of DNA via the polymerase enzyme – we could watch the process live”, says Frank Vollmer. Biochemists could then observe the enzyme as it copies genetic information, and could even read the exact sequence of letters in the genetic code from the nanosensor signal. 

Why the machinery of life stalls

Vollmer’s team’s future vision is to scan molecules, atom for atom: “If we utilize different sources of light, it will be possible to completely read molecules”, plans Vollmer. With this kind of molecular scanner, a process can be observed from various perspectives and at very short intervals. This would significantly improve our understanding of molecular processes. Biologists would be able to observe in great detail the way that structures change, in time spans ranging from nanoseconds to several hours. In addition, the idea of an automated laboratory that is no larger than a fingernail and can scan a blood or urine sample, protein by protein, to diagnose diseases on a molecular level is within reach.

If, in the future, we are able to track the way in which enzymes change shape, physicians may be better able to understand why the machinery of life stalls in certain cases and an organism becomes ill. Several diseases, such as Alzheimer’s, are connected to changes in the structure of proteins. More detailed insight into such processes could even deliver departure points for new therapies.



Prof Frank Vollmer

e-mail: frank.vollmer(at)mpl.mpg(dot)de


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