Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New Technique Boosts Protein NMR Imaging Speeds

11.02.2009
A group led by a UIC chemist has found a way to shorten the time needed to obtain molecular structure imaging information from solid-state NMR. They've also found a way to use smaller imaging samples to obtain spectral imaging data and reduce experiment costs.

Solid-state nuclear magnetic resonance, or SSNMR, is a valuable tool to image and analyze the chemical makeup of proteins and other biomolecules. But the imaging process is time-consuming and requires large amounts of costly isotope-labeled sample for study.

Yoshitaka Ishii, associate professor of chemistry at the University of Illinois at Chicago, believes he has found a quicker and more efficient approach to using SSNMR called paramagnetic relaxation-assisted condensed data collection, or PACC. Details of the approach are reported in the March issue of Nature Methods (online Feb. 8.)

Ishii and his associates found a way of increasing sensitivity of SSNMR by doping samples at varying concentrations with the paramagnetic copper-acid solution Cu-EDTA, a chemical used in many industrial applications. That made the study samples more active transponders, providing strong signals and detailed spectral information with minimal downtime.

"With SSNMR, we collect the signal responses but then have to wait for the SSNMR system to recycle, which takes up to three seconds," said Ishii. "You have to do this hundreds of times. And during most of that time, you're basically doing nothing. By our approach, we've reduced that waiting period by up to 20 times."

Ishii said the slow process of gathering spectral signal information has been the "de facto standard for over 20 years." He found it shocking how much time is spent just waiting for results using traditional SSNMR.

The chemists also boosted the SSNMR efficiency by using a spinning speed of 40 kilohertz, instead of the usual 10 kHz, and doing a fast recycling of low radio frequency field power sequences, which minimizes the amount of irradiation heat surrounding the study sample.

"The radio frequency irradiation process typically increases temperature, but we worked it so we could get a signal without strong irradiation, which could fry out a protein," said Ishii.

Ishii and his group studied various types of molecules using this new approach, including the amyloid fibrils often associated with Alzheimer's disease, larger globular proteins and cytoskeleton proteins. The new approach worked well with each type.

The doping solution they added to enhance the sensitivity of samples did not change the chemical structure of proteins studied. Ishii said the approach also enabled his group to get useful spectral signals using much smaller samples.

"We often need samples as large as 10 microliters, but with this approach we can use as little as one microliter or less," he said. "With protein structure work, preparing samples is a major bottleneck, which limits our ability to analyze it. This approach opens up the possibility for more difficult structure determination work."

Ishii hopes the PACC approach may be enhanced to achieve even greater SSNMR sensitivity, but notes the technique, as presently tested, should allow study of molecular structural features that are currently difficult to obtain using other laboratory methods.

The study's lead author is Nalinda Wickramasinghe, Ishii's former UIC doctoral student. Other authors include Leslie Wo-Mei Fung, professor of chemistry at UIC, and Ago Samoson of the National Institute of Chemical Physics and Biophysics in Tallinn, Estonia and the University of Warwick in Coventry, U.K.

Funding for the work came from the National Science Foundation, the National Institutes of Health, the Dreyfus Foundation and the Alzheimer's Association.

Paul Francuch | Newswise Science News
Further information:
http://www.uic.edu

More articles from Life Sciences:

nachricht Nerves control the body’s bacterial community
26.09.2017 | Christian-Albrechts-Universität zu Kiel

nachricht Ageless ears? Elderly barn owls do not become hard of hearing
26.09.2017 | Carl von Ossietzky-Universität Oldenburg

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The fastest light-driven current source

Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.

Graphene is up to the job

Im Focus: LaserTAB: More efficient and precise contacts thanks to human-robot collaboration

At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.

Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Nerves control the body’s bacterial community

26.09.2017 | Life Sciences

Four elements make 2-D optical platform

26.09.2017 | Physics and Astronomy

Goodbye, login. Hello, heart scan

26.09.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>