Knowing the structure of a molecule is an important part of understanding it, but quite often it’s even more important to know how the molecule moves — more specifically, the vibrational dynamics that drive and control its interactions with other molecules in chemical reactions. That’s particularly true of proteins, the enormously complex molecular structures found at the heart of important life processes such as cell signaling, ion transport, and other functions. But most of the available techniques for studying the vibrational properties of a protein run into some vexing limitations, especially when probing the lower frequencies at which the proteins actually do their job. A team of researchers have found a way around that problem by using the X-ray Science Division 3-ID x-ray beamline at the U.S. Department of Energy Office of Science’s Advanced Photon Source (APS) at Argonne National Laboratory to investigate the iron-based heme molecules at the reactive core of a multitude of proteins, such as hemoglobin. Their work provides new information about the vibrational dynamics of hemes. Read more…