'Amplifying' the Fine Details Of Molecular Structure Is a Gas

摘要

Proteins and other molecules are quiet--too quiet, say scientists straining to detect the signals that might reveal their structure. Certain atoms on molecules resonate at unique frequencies in a magnetic field, giving off signals that can indicate what these molecules are made of. But these signatures are inherently weak, even from the most abundant atoms, such as hydrogen. So researchers using this method, called nuclear magnetic resonance (NMR) spectroscopy, struggle to make out the fine details.Now on page 1848 of this issue, a group of researchers from the University of California, Berkeley, Lawrence Berkeley National Laboratory, and Tel Aviv University in Israel report a way to get the atoms to sound off at a higher level. They can boost theresonance signals of hydrogen atoms at least twofold by using xenon gas as a "preamplifier." The xenon atoms are pretreated to give off a powerful magnetic signal, and they in turn raise the volume of the hydrogens when the two types of atoms come in contact. If the effect works with other atoms such as carbon-13--and the researchers say there's no reason why it shouldn't--NMR spectroscopists could bubble xenon gas into solutions spiked with proteins or other molecules and get a loud response.