The process of engineering proteins as components of molecular machine systems leading toward advanced nanotechnology may be accelerated by a recent report that confining enzymes inside nanopores leads to altered and enhanced enzymatic activity. Thanks to Physorg.com for pointing to this news release from Rensselaer Polytechnic Institute “Nano Fit-ness: Helping Enzymes Stay Active and Keep in Shape“:
…Rensselaer Polytechnic Institute Professor Marc-Olivier Coppens has developed a new technique for boosting the stability of enzymes, making them useful under a much broader range of conditions. Coppens confined lysozyme and other enzymes inside carefully engineered nanoscale holes, or nanopores. Instead of denaturing, these embedded enzymes mostly retained their 3-D structure and exhibited a significant increase in activity.
“Normally, when you put an enzyme on a surface, its activity goes down. But in this study, we discovered that when we put enzymes in nanopores — a highly controlled environment — the enzymatic activity goes up dramatically,” said Coppens, a professor in the Department of Chemical and Biological Engineering at Rensselaer. “The enzymatic activity turns out to be very dependent on the local environment. This is very exciting.”
Results of the study are detailed in the paper, “Effects of surface curvature and surface chemistry on the structure and activity of proteins adsorbed in nanopores,” published last month by the journal Physical Chemistry Chemical Physics. The paper may be viewed online at: http://dx.doi.org/10.1039/C0CP02273J
Researchers at Rensselaer and elsewhere have made important discoveries by wrapping enzymes and other proteins around nanomaterials. While this immobilizes the enzyme and often results in high stability and novel properties, the enzyme’s activity decreases as it loses its natural 3-D structure.
Coppens took a different approach, and inserted enzymes inside nanopores. Measuring only 3-4 nanometers (nm) in size, the enzyme lysozyme fits snugly into a nanoporous material with well-controlled pore size between 5 nm and 12 nm. Confined to this compact space, the enzymes have a much harder time unfolding or wiggling around, Coppens said.
The discovery raises many questions and opens up entirely new possibilities related to biology, chemistry, medicine, and nanoengineering, Coppens said. He envisions this technology could be adapted to better control nanoscale environments, as well as increase the activity and selectivity of different enzymes. Looking forward, Coppens and colleagues will employ molecular simulations, multiscale modeling methods, and physical experiments to better understand the fundamental mechanics of confining enzymes inside nanopores. …
The abstract of the published research states that both the size and chemical functionality of the confining nanopore affect both the secondary structure and the catalytic activity of the confined enzyme.
The intricately organized systems of molecular machines that make up living cells provide the existence proof that advanced nanotechnology with high throughput atomically precise manufacturing is possible. This research adds to our knowledge of how to use these molecular machines outside the carefully controlled environment of the cell. The ability to engineer the nanoscale environment of enzymes using currently available nanotechnology provides more tools than we thought we had available to adapt biology to the purposes of generalized molecular manufacturing.
