Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Methuselah enzymes: SEN and the art of molecule maintenance

02.04.2004


Single-enzyme nanoparticles, or SENs, left, and their thinner cousins, right, remain active for up to 143 days, thanks to their protective caging. (J.B. Kim, Pacific Northwest National Laboratory.)


Lab discovers way to keep short-lived catalysts active for longer than five months

Enzymes, the workhorses of chemical reactions in cells, lead short and brutal lives. They cleave and assemble proteins and metabolize compounds for a few hours, and then they are spent.

This sad fact of nature has limited the possibilities of harnessing enzymes as catalytic tools outside the cell, in uses that range from biosensing to toxic waste cleanup.



To increase the enzyme’s longevity and versatility, a team at the Department of Energy’s Pacific Northwest National Laboratory in Richland, Wash., has caged single enzymes to create a new class of catalysts called SENs, or single enzyme nanoparticles. The nanostructure protects the catalyst, allowing it to remain active for five months instead of hours.

"The principal concept can be used with many water-soluble enzymes," said Jungbae Kim, PNNL senior scientist who described the feat here today at the national meeting of the American Chemical Society.

"Converting free enzymes into these novel enzyme-containing nanoparticles can result in significantly more stable catalytic activity," added Jay Grate, PNNL laboratory fellow and SENs co-inventor.

Kim and Grate, working in the W.R. Wiley Environmental Molecular Sciences Laboratory at PNNL, modified a common protein-splitting enzyme called alpha-chymotrypsin. They modified the enzyme surface to make it soluble, then added vinyl reagents to induce the growth of molecular threads, or polymers, from the enzyme surface. A second polymerization step cross-linked silicon chains, forming a basketball-netlike structure a few nanometers thick. What result are SENs that appear in electron microscopic images as hollow enzyme-containing nanostructures about 8 nanometers across. Kim and Grate found that by using less reactive forms of vinyl they could vary the thickness of the nano-netting by half. Thick or thin, the porous netting preserves the shape of the enzyme inside yet allows its active site to interact with a substrate. SENs are also amenable to storage; they have been refrigerated for five months, losing little of their activity.

Among the uses Kim noted for SENs is the breakdown toxic waste-a single treatment could last months. Stabilized enzymes are also a prerequisite for many types of biosensors. And they may be of interest for coating surfaces, with application ranging from medicine (protecting implants from protein plaques) to shipping (keeping barnacles off hulls). PNNL is investigating several other applications in the environmental and life sciences.

PNNL is a DOE Office of Science laboratory that solves complex problems in energy, national security, the environment and life sciences by advancing the understanding of physics, chemistry, biology and computation. PNNL employs 3,800, has a $600 million annual budget, and has been managed by Ohio-based Battelle since the lab’s inception in 1965.

Bill Cannon | PNNL
Further information:
http://www.pnl.gov/news/2004/04-24.htm

More articles from Life Sciences:

nachricht What the world's tiniest 'monster truck' reveals
23.08.2017 | American Chemical Society

nachricht Treating arthritis with algae
23.08.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>