New Method for Studying Molecules Discovered

Researchers at Queen's University have discovered the method for studying oxygen in large molecular systems. The findings will help in the study of proteins, DNA, RNA and other molecular structures.

Biological molecules make up all living creatures on earth and contain four major elements -- hydrogen, carbon, nitrogen and oxygen. But until now scientists were only able to use nuclear magnetic resonance (NMR) to study three out of the four elements in the molecule puzzle because oxygen wavelengths were difficult to detect.
"Oxygen signals were so weak, so to speak, that no one could make use of them," says chemistry professor Gang Wu. "Now there is a way of detecting them even in complex biomolecular systems."
Dr. Wu and his colleagues used one of the strongest NMR spectrometers in the world, located at the National Ultrahigh-Field NMR Facility for Solids in Ottawa, to create a magnetic field in which oxygen's wavelength could be detected. They also enriched the oxygen in the molecule using isotope enrichment, and implemented new NMR techniques to boost the sensitivity for detecting weak signals.
The result is an amplified oxygen wavelength that can be studied. Scientists can now examine all four major elements and learn more about the chemical structure and interaction of large molecules.
Dr. Wu's colleagues include lead author and Queen's post-doctoral fellow Jianfeng Zhu, Eric Ye (University of Ottawa) and Victor Terskikh (NRC Steacie Institute for Molecular Sciences).

Nuclear Magnetic Resonance [NMR]

Nuclear magnetic resonance was first described independently by Felix Bloch and Edward Mills Purcell, in 1946, both of whom shared the Nobel Prize in physics in 1952 for their discovery.
Nuclear magnetic resonance (NMR) is a physical phenomenon based upon the quantum mechanical magnetic properties of an atom's nucleus. All nuclei that contain odd numbers of protons or neutrons have an intrinsic magnetic moment and angular momentum. The most commonly measured nuclei are hydrogen-1 (the most receptive isotope at natural abundance) and carbon-13, although nuclei from isotopes of many other elements can also be observed. NMR studies magnetic nuclei by aligning them with a very powerful external magnetic field and perturbing this alignment using an electromagnetic field. The resulting response to the external perturbing electromagnetic magnetic is the phenomenon that is exploited in nuclear magnetic resonance spectroscopy and magnetic resonance imaging.