Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Night of the living enzyme

30.11.2006
Nano-chambers mimic living cells to squeeze new activity from stale, defunct proteins

Inactive enzymes entombed in tiny honeycomb-shaped holes in silica can spring to life, scientists at the Department of Energy’s Pacific Northwest National Laboratory have found.

The discovery came after salvaging enzymes that had been in a refrigerator long past their expiration date. Enzymes are proteins that are not actually alive but come from living cells and perform chemical conversions.

To the research team’s surprise, enzymes that should have fizzled months before perked right up when entrapped in a nanomaterial called functionalized mesoporous silica, or FMS. The result points the way for exploiting these enzyme traps in food processing, decontamination, biosensor design and any other pursuit that requires controlling catalysts and sustaining their activity.

... more about:
»FMS »Pore »activity »author »enzyme

“There’s a school of thought that the reason enzymes work better in cells than in solution is because the concentration of enzymes surrounded by other biomolecules in cells is about 1,000 to 10,000 time more than in standard biochemistry lab conditions,” said Eric Ackerman, PNNL chief scientist and senior author of a related study that appears today in the journal Nanotechnology. “This crowding is thought to stabilize and keep enzymes active.”

The silica-spun FMS pores, hexagons about 30 nanometers in diameter spread across a sliver of material, mimic the crowding of cells. Ackerman, lead author Chenghong Lei and colleagues said crowding induces an unfolded, free-floating protein to refold; upon refolding, it reactivates and becomes capable of catalyzing thousands of reactions a second.

The FMS is made first, and the enzymes are added later. This is important, the authors said, because other schemes for entrapping enzymes usually incorporate the material and enzymes in one harsh mixture that can cripple enzyme function forever.

In this study, the authors reported having “functionalized” the silica pores by lining them with compounds that varied depending on the enzyme to be ensnared—amine and carboxyl groups carrying charges opposite that of three common, off-the-shelf biocatalysts: glucose oxidase (GOX), glucose isomerase (GI) and organophosphorus hydrolase (OPH).

Picture an enzyme in solution, floating unfolded like a mop head suspended in a water bucket. When that enzyme comes into contact with a pore, the protein is pulled into place by the oppositely charged FMS and squeezed into active shape inside the pore. So loaded, the pore is now open for business; substances in the solution that come into contact with the enzyme can now be catalyzed into the desired product. For example, GI turns glucose to fructose, and standard tests for enzyme activity confirmed that FMS-GI was as potent or better at making fructose as enzyme in solution. OPH activity doubled, while GOX activity varied from 30 percent to 160 percent, suggesting that the enzyme’s orientation in the pore is important.

“It could be that in some cases the active site, the part of the enzyme that needs to be in contact with the chemical to be converted, was pointing the wrong way and pressed tightly against the walls of the pore,” Ackerman said.

To show that the enzymes were trapped inside the FMS pores, the team stained the protein-FMS complex with gold nanoparticles and documented the enzyme-in-pore complex through electron microscopy. A spectroscopic analysis of the proteins squeezed into their active conformation turned up no new folds, evidence that they had neatly refolded rather than been forcibly wadded into the pore.

Ackerman said that this new understanding combined with new cell-free techniques—making hundreds of designer enzymes a day with components derived from cells—will speed the development of task-specific enzymes. This could lead to “enzyme-based molecular machines in nanomaterials that carry out complex biological reactions to produce energy or remediate toxic pollutants.”

Bill Cannon | EurekAlert!
Further information:
http://www.pnl.gov

Further reports about: FMS Pore activity author enzyme

More articles from Life Sciences:

nachricht Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

OLED production facility from a single source

29.03.2017 | Trade Fair News

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>