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 reports about: > Cu-EDTA > NMR > PACC > Protein > Protein NMR Imaging Speeds > SSNMR > Solid-state nuclear magnetic resonance > UIC > biomolecules > cytoskeleton proteins > globular proteins > molecular structure imaging > paramagnetic copper-acid solution > paramagnetic relaxation-assisted condensed data collection > spectral imaging data
Novel mechanisms of action discovered for the skin cancer medication Imiquimod
21.10.2016 | Technische Universität München
Second research flight into zero gravity
21.10.2016 | Universität Zürich
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
COMPAMED has become the leading international marketplace for suppliers of medical manufacturing. The trade fair, which takes place every November and is co-located to MEDICA in Dusseldorf, has been steadily growing over the past years and shows that medical technology remains a rapidly growing market.
In 2016, the joint pavilion by the IVAM Microtechnology Network, the Product Market “High-tech for Medical Devices”, will be located in Hall 8a again and will...
'Ferroelectric' materials can switch between different states of electrical polarization in response to an external electric field. This flexibility means they show promise for many applications, for example in electronic devices and computer memory. Current ferroelectric materials are highly valued for their thermal and chemical stability and rapid electro-mechanical responses, but creating a material that is scalable down to the tiny sizes needed for technologies like silicon-based semiconductors (Si-based CMOS) has proven challenging.
Now, Hiroshi Funakubo and co-workers at the Tokyo Institute of Technology, in collaboration with researchers across Japan, have conducted experiments to...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
21.10.2016 | Health and Medicine
21.10.2016 | Information Technology
21.10.2016 | Materials Sciences