A new 1.5-mm high-temperature superconducting probe designed to detect carbon 13 will significantly enhance studies in natural products and metabolomics.
Ten years ago the 900 Ultra-Wide Bore magnet became available to an international user community for Nuclear Magnetic Resonance spectroscopy and Magnetic Resonance Imaging at the National High Magnetic Field Lab. Since then 69 publications have been published from this instrument spanning many disciplines and the number of publications per year continues to increase with 26 in just the past 18 months demonstrating that state of the art data continues to be collected on this superb magnet.
This week at the lab, engineers are fine-tuning a new magnet that will offer scientists a novel way to do nuclear magnetic resonance (NMR).
The magnet, along with a new cabinet and console, comprise the lab’s new 600 MHz spectrometer, which will be used for a new measurement technique with a very long name: magic angle spinning dynamic nuclear polarization. MAS DNP, as it is more reasonably called, gives scientists deciphering the structure of molecules a clearer picture of what they are looking at.
The 2,000-pound Bruker superconducting magnet was installed earlier this month, connected to cryogen and a power supplies, and ramped up to full field, 14.1 teslas. A special feature of the instrument is a second, small, "sweepable" magnet coil that allows scientists to fine-tune the field and frequency of the instrument.
In NMR spectroscopy, scientists put the material they are studying – let’s say a protein – inside the magnet, then direct radio waves of a specific frequency at it. These in turn send back signals identifying certain atoms, thus helping scientists piece together the sample’s structure. In the MAS DNP technique, a solvent containing free radicals is added to the sample. When irradiated with microwaves, the result is much stronger NMR signals and thus a clearer idea of the material’s structure.
This new setup, located in the MagLab’s Nuclear Magnetic Resonance and Magnetic Resonance Imaging / Spectroscopy Facility, is among just a few in the world and the only one open to outside scientists, said Thierry Dubroca, a MagLab physicist who has helped develop the capability. The new system will be available to scientists in early 2016. Scientists interested in using MAS DNP should contact Thierry Dubroca, Zhehong Gan, Ivan Hung, Joanna Long.
Video by Stephen Bilenky / Text by Kristen Coyne
Biomedical researchers have a unique tool to investigate a variety of living and excised specimen with the MagLab’s 21.1 T 900-MHz ultra-widebore (105-mm) vertical magnet. However, there are challenges to performing research in a high-field vertical magnet, which have been addressed by a NHMFL-led team of international scientists working to make very high field or ultra high field MRI more flexible. This team has constructed a tunable sliding ring transmit/receive volume coil for 900-MHz hydrogen MRI that provides the uniformity and sensitivity for high resolution and functional imaging of living samples while accommodating unique excised samples to improve characterization and throughput. This new design incorporates the apparatus necessary for maintaining animals in a vertical position while providing remote tuning and sample flexibility beyond most available coils.
A MagLab chemist has determined how the flu virus tunnels into cells, paving the way for new treatments.
Inspired by the SIM card technology used in modern cell phones, MagLab engineers designed and built a versatile magnet probe that makes it easier and more efficient for scientists to see the structure of molecules.
The MagLab’s AMRIS facility has recently implemented dissolution DNP technology. The system utilizes a 5 T magnet in which samples are cooled to 14,000 gain in SNR on dissolution and injection into our 4.7T MRI/S scanner.
This week at the lab, a pair of chemists are conducting a nuclear magnetic resonance (NMR) experiment ... from halfway across the country.
Oklahoma State University chemistry professor Smita Mohanty and postdoc Mohiuddin Ovee have been spending several weeks collecting NMR data on a membrane protein that plays a critical role in the proper function of living organisms. The data is helping them create two- and three-dimensional images of the protein and determine its structure, work that may shed light on a serious genetic defect in humans that is associated with the protein.
Thanks to special software and expert on-site support from MagLab technician Ashley Blue, Mohanty and Ovee are collecting data in real time from an 800 MHz NMR magnet located in Tallahassee, Florida, without ever leaving the Sooner state. About 10 percent of scientists who conduct experiments in our NMR magnets do their research remotely.
Mohanty said the process was user-friendly and efficient, with Blue on hand to handle any snafus. “It was amazing that we could tune the probe, shim the magnet and calibrate other parameters on the magnet located at the MagLab while sitting in our computer at Oklahoma State University,” said Mohanty, who is conducting her first experiment at the facility.
Tim Cross, director of the MagLab's NMR Facility, said this kind of long-distance science is increasingly common. "As NMR instruments become more expensive, it is more important for users to transition to running experiments remotely in state-of-the-art facilities like those at the MagLab," he said.
Photos: Courtesy SMITA MOHANTY (above left); STEPHEN BILENKY (above right) / Text by KRISTEN COYNE
Structures of antimicrobial peptides piscidins 1 and 3 were solved in two bacterial cell mimics by oriented sample solid-state NMR. A significant finding of this work is that in contrast to the ideal structures shown in mechanistic studies of AMPs, the structures of both peptides are disrupted and kinked at a conserved central glycine, which results in stronger interactions with the lipid bilayers. The more pronounced imperfect amphipathicity of piscidin 1 over piscidin 3 that is revealed helps better understand why the former more effectively mixes the lipids as needed to induce the greatest damage to bacterial cells.
From nanorockets to nanocages, good science can come in tiny packages — all with the aim of solving really big problems.