The body is an almost perfect machine. For it to function properly, each individual component, that is each molecule, must reliably fulfill its specific function. Each molecule must thus “recognize” other molecules and work with them. A team of researchers from the Max Planck Institute for Solid State Research in Stuttgart, the Fraunhofer Institute in Freiburg, and King’s College in London, has now successfully filmed pairs of molecules during the recognition process. As reported to the journal Angewandte Chemie, the shapes of the molecules change to accommodate each other.
Like humans, molecules also “greet” each other with a kind of “handshake”. Anyone who has tried to shake someone’s right hand with his or her own left will have had a little trouble: the right and left hands do not fit together. In the same way, some molecules that exist in both a right-handed (D) and left-handed (L) configuration can tell if others they encounter are the D or L form.
Magali Lingenfelder and colleagues at the Max Planck Institute for Solid State Research have now been able to use scanning tunneling microscopy to take a series of pictures that follow in detail the “encounters” of diphenylalanine molecules adsorbed onto a substrate. (Diphenylalanine is the central structural unit within polypeptide fibers found in the brains of Alzheimer’s patients.) The “film sequences” reveal that only molecules with the same chirality (handedness) readily aggregate into pairs and chains.
Just as in a handshake, it is not enough that the right hands hold each other. To grip each other firmly, the two hands must adapt to fit their shapes together. Molecules do the same: close examination of the “film”, in conjunction with theoretical calculations by researchers from King’s College, prove that this type of dynamic accommodation of shape also occurs when two molecules “shake hands”.
“Our work finally demonstrates that Linus Pauling was right with his theory of intermolecular conformation of over 50 years ago,” says Lingenfelder. “In molecular recognition, it is not so much the static forms that are important, but rather how well the molecules can conform to each other.”
Author: Magalí Lingenfelder, Max-Planck-Institut für Festkörperforschung, Stuttgart (Germany), http://www.fkf.mpg.de/kern/res_team/index.html
Title: Tracking the Chiral Recognition of Adsorbed Dipeptides at the Single-Molecule Level
Angewandte Chemie International Edition, doi: 10.1002/anie.200700194
Colorectal cancer risk factors decrypted
13.07.2018 | Max-Planck-Institut für Stoffwechselforschung
Algae Have Land Genes
13.07.2018 | Julius-Maximilians-Universität Würzburg
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.
Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
13.07.2018 | Event News
13.07.2018 | Materials Sciences
13.07.2018 | Life Sciences