Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The Molecular Breakdance of Seeing

17.11.2015

Our sense of vision is based on highly choreographed, ultrafast molecular motions.

The detection of light by pigments in the retina, called rhodopsin or visual purple, leads to our sense of vision. New experiments by scientists from the Max Planck Institute for the Structure and Dynamics of Matter and the University of Toronto have revealed that the primary photochemical event of this process operates at the fundamental molecular speed limit. These results are reported online in the journal Nature Chemistry today.


Artist's impression of the molecular motion in the retina.

J.M. Harms, MPSD

The retinal chromophore in rhodopsin, also called vitamin A aldehyde, derives its light sensitivity from a repeating chain of single- and double-bonded carbon atoms. The absorption of a photon by retinal causes an extremely short transient weakening of a specific double bond resulting in rotation about that bond.

Pinpointing how fast this so-called chemical isomerization reaction occurs has been difficult, however, and has largely tracked the technological advances in pulsed laser sources. With femtosecond lasers it was shown that the isomerization takes place within 200 femtoseconds (that is 200 millionths of a billionth of a second), and is likely a vibrationally-coherent chemical reaction, meaning the vibrational motions of the retinal chromophore itself help directing the isomerization reaction.

Using a highly sensitive technique from the field of ultrafast spectroscopy called heterodyne-detected transient grating spectroscopy, scientists in the laboratories of Professors R. J. Dwayne Miller (University of Toronto and Max Planck Institute for the Structure and Dynamics of Matter) and Oliver P. Ernst (University of Toronto) revisited the isomerization reaction of bovine rhodopsin with unprecedented sensitivity and temporal resolution.

Such an approach revealed that the isomerization takes place on a timescale of 30 femtoseconds. “It turns out that the primary step of vision is nearly ten times faster than anyone thought,” says Professor Miller, “and the atomic motions are all perfectly choreographed by the protein.”

Temporal analysis of the experimental data revealed these choreographed vibrational dynamics, which are comprised of localized stretching, out-of-plane wagging, and torsional motions. “Such a fast timescale sets distinct limitations on the vibrationally-coherent reaction coordinate,” says Dr. Philip Johnson, lead author of the study, "and this work indicates that it is local to the specific isomerizing double bond.”

“Moreover,” he adds, “the isomerization reaction proceeds within a single period of the relevant torsional vibrational motion. The notion of fully vibrationally-coherent chemical reactions has been around since at least the 1930s, but really hasn't been explicitly observed until now.”

This research was supported by the Max Planck Society, the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canada Excellence Research Chairs program (CERC), and the Canadian Institute for Advanced Research (CIFAR). Professor Miller and Professor Ernst are co-directors of CIFAR’s program Molecular Architecture of Life, which is untangling the details of the complex molecular processes that underlie all living systems.

Contact person:
Prof. Dr. R. J. Dwayne Miller
Max Planck Institute for the Structure and Dynamics of Matter
Center for Free-Electron Laser Science
Luruper Chaussee 149
22761 Hamburg
Germany
+49 (0)40 8998-6200
dwayne.miller@mpsd.mpg.de

Original publication:
Philip J. M. Johnson, Alexei Halpin, Takefumi Morizumi, Valentyn I. Prokhorenko, Oliver P. Ernst, and R. J. Dwayne Miller, “Local vibrational coherences drive the primary photochemistry of vision,” Nature Chemistry 7, 980–986 (2015), DOI: 10.1038/nchem.2398

Weitere Informationen:

http://dx.doi.org/10.1038/nchem.2398 Original publication
http://www.mpsd.mpg.de/mpsd/research/ard Research group of Prof. Dr. R. J. Dwayne Miller
http://www.mpsd.mpg.de/en Max Planck Institute for the Structure and Dynamics of Matter

Dr. Michael Grefe | Max-Planck-Institut für Struktur und Dynamik der Materie

More articles from Life Sciences:

nachricht Scientists enlist engineered protein to battle the MERS virus
22.05.2017 | University of Toronto

nachricht Insight into enzyme's 3-D structure could cut biofuel costs
19.05.2017 | DOE/Los Alamos National Laboratory

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

Im Focus: Hydrogen Bonds Directly Detected for the First Time

For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.

Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

Media accreditation opens for historic year at European Health Forum Gastein

16.05.2017 | Event News

 
Latest News

New approach to revolutionize the production of molecular hydrogen

22.05.2017 | Materials Sciences

Scientists enlist engineered protein to battle the MERS virus

22.05.2017 | Life Sciences

Experts explain origins of topographic relief on Earth, Mars and Titan

22.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>