Volume 90 Issue 4 | p. 28 | Concentrates
Issue Date: January 23, 2012

Nanotube Detects Enzyme Motion

Researchers track the motions of a single enzyme by attaching it to a carbon nanotube in a field-effect transistor
Department: Science & Technology
News Channels: Analytical SCENE, Biological SCENE, Materials SCENE
Keywords: lysozyme, enzyme movement, carbon nanotube, field-effect transistor
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A schematic shows T4 lysozyme hydrolyzing a polysaccharide while tethered to a nanotube FET.
Credit: Philip G. Collins/UC Irvine
Lysozyme anchored to a nanotube hydrolyzes polysaccharide
 
A schematic shows T4 lysozyme hydrolyzing a polysaccharide while tethered to a nanotube FET.
Credit: Philip G. Collins/UC Irvine

Enzymes and nanotubes may seem unlikely partners in a molecular two-step. But by tethering lysozyme to the carbon nanotube in a field-effect transistor (FET), scientists are now able to electronically monitor the enzyme’s movements (Science, DOI: 10.1126/science.1214824). This approach gives researchers a new way to follow enzyme movement over relatively long periods of time—something that can be difficult to do with fluorescence techniques because of signal bleaching. Gregory A. Weiss, Philip G. Collins, and colleagues from the University of California, Irvine, modified T4 lysozyme, an enzyme that hydrolyzes polysaccharides in bacterial cell walls, by covalently attaching a pyrene anchor to one of its cysteine residues. The pyrene then associates via π–π interactions to the single-walled carbon nanotube that makes up the FET’s conductive channel. As the enzyme moves, the FET detects changes in electrostatic potentials. In this manner, the researchers were able to tune into two different hinge-bending motions in the enzyme: one that comes from the hydrolysis of the polysaccharide and one that arises from nonproductive binding events.

 
Chemical & Engineering News
ISSN 0009-2347
Copyright © American Chemical Society

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