Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

Home > Press > Small and efficient - water nanodroplets cool biomolecules ultrafast

Upper left: Schematic of a reverse micelle consisting of phospholipid molecules. The phosphate groups of the lipid molecules (blue spheres) are arranged at the inner surface of the micelle. Water molecules are located in the inner part of the micelle. Upper right: Enlarged view of the structure of a phospholipid molecule. Oxygen atoms are shown in red, hydrogen atoms in white, carbon atoms in grey, the nitrogen atom in blue, and the phosphorus atom in orange. The angled water molecules are arranged around the phosphate (PO4) group. Lower part: Scheme of energy transfer. In the experiments, the (asymmetric) phosphate vibration is initially excited (red oxygen atoms). The energy released in the decay of the vibration is transferred to the surrounding water shell (red H2O molecules) within 1 ps.
Upper left: Schematic of a reverse micelle consisting of phospholipid molecules. The phosphate groups of the lipid molecules (blue spheres) are arranged at the inner surface of the micelle. Water molecules are located in the inner part of the micelle. Upper right: Enlarged view of the structure of a phospholipid molecule. Oxygen atoms are shown in red, hydrogen atoms in white, carbon atoms in grey, the nitrogen atom in blue, and the phosphorus atom in orange. The angled water molecules are arranged around the phosphate (PO4) group. Lower part: Scheme of energy transfer. In the experiments, the (asymmetric) phosphate vibration is initially excited (red oxygen atoms). The energy released in the decay of the vibration is transferred to the surrounding water shell (red H2O molecules) within 1 ps.

Abstract:
Researchers of the Max-Born-Institute at Berlin, Germany, have observed how biomolecules transfer energy into extremely small water droplets in their environment. A water shell consisting of only 3 water molecules around a phospholipid molecule is sufficient for energy transfer within 1 ps.

Small and efficient - water nanodroplets cool biomolecules ultrafast

Berlin, Germany | Posted on December 2nd, 2012

Biochemical processes occur mainly in an aqueous environment. Particular groups of a biomolecule are embedded in a shell of water molecules, a process called hydration. The water shell stabilizes the biomolecular structure and enables an exchange of energy between the biomolecule and its environment. Examples are the double helix of DNA, the carrier of basic genetic information, in an aqueous medium and the membranes of living cells which consist of phospholipids. The molecular mechanisms, the speed and the efficiency of energy exchange between the biomolecule and the water shell are understood only in part and, thus, a topic of current basic research.

Scientists of the Max-Born-Institute have shown that extremely small water droplets embedding a phospholipid molecule enable efficient energy transfer on a time scale of 1 ps (1 ps = 10-12 s = 1 millionth of a millionth of a second). René Costard, Christian Greve, Ismael Heisler, and Thomas Elsaesser report in the current issue of Journal of Physical Chemistry Letters (vol.3, page 3646, 2012) that 3 water molecules around the phosphate group of the phospholipid are sufficient for transferring the energy of vibrations from the phospholipid into this minimal water shell. The transferred energy heats the water shell by 10 to 20 centigrades. The thermal energy is stored in tilting motions of water molecules, so called librations, and leads to a weakening of the interaction between the water molecules, the so called hydrogen bonds. The overall molecular structure of the water shell remains practically unchanged. This extremely efficient mechanism of energy disposal allows for the transfer of even larger amounts of energy, protecting the biomolecule against damage by overheating.

The researchers studied a phospholipid model system consisting of the DOPC molecules shown in Fig. 1. The molecules are arranged in so-called reverse micelles which contain the water molecules hydrating the phosphate groups. In this geometry, the hydration level, i.e., water content, can be changed in a wide range. For studying energy transfer, either phosphate vibrations of the phospholipid or OH stretching vibrations of water are excited by an infrared pulse of a 0.1 ps duration. The vibrations decay within a fraction of a picosecond and the energy released in this decay is transferred into the water shell. The transfer and redistribution of energy is mapped via transient two-dimensional infrared spectra of the OH stretching vibration of water. The weakening of hydrogen bonds in the heated water shell leads to a shift of the OH stretching spectra to higher frequencies. Measuring the change of the two-dimensional spectra as a function of time provides direct insight into the energy transfer dynamics.

Full bibliographic informationR. Costard, C. Greve, I. A. Heisler, T. Elsaesser: Ultrafast energy redistribution in local hydration shells of phospholipids: a two-dimensional infrared study. J. Phys. Chem. Lett. 3, 3646 (2012).

####

For more information, please click here

Contacts:
Thomas Elsaesser

Copyright © AlphaGalileo

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

MEMS chips get metatlenses: Combining metasurface lenses with MEMS technology could add high-speed scanning and enhance focusing capability of optical systems February 21st, 2018

Atomic structure of ultrasound material not what anyone expected February 21st, 2018

Oxford Instruments announces Dr Kate Ross as winner of the 2018 Lee Osheroff Richardson Science Prize for North and South America February 20th, 2018

Computers aid discovery of new, inexpensive material to make LEDs with high color quality February 20th, 2018

Physics

Liquid crystal molecules form nano rings: Quantized self-assembly enables design of materials with novel properties February 7th, 2018

New exotic phenomena seen in photonic crystals: Researchers observe, for the first time, topological effects unique to an “open” system January 12th, 2018

Columbia engineers create artificial graphene in a nanofabricated semiconductor structure: Researchers are the first to observe the electronic structure of graphene in an engineered semiconductor; finding could lead to progress in advanced optoelectronics and data processing December 13th, 2017

Leti Develops World’s First Micro-Coolers for CERN Particle Detectors: Leti Design, Fabrication and Packaging Expertise Extends to Very Large Scientific Instruments December 11th, 2017

Discoveries

MEMS chips get metatlenses: Combining metasurface lenses with MEMS technology could add high-speed scanning and enhance focusing capability of optical systems February 21st, 2018

Atomic structure of ultrasound material not what anyone expected February 21st, 2018

Computers aid discovery of new, inexpensive material to make LEDs with high color quality February 20th, 2018

Unconventional superconductor may be used to create quantum computers of the future: They have probably succeeded in creating a topological superconductor February 19th, 2018

Announcements

MEMS chips get metatlenses: Combining metasurface lenses with MEMS technology could add high-speed scanning and enhance focusing capability of optical systems February 21st, 2018

Atomic structure of ultrasound material not what anyone expected February 21st, 2018

Oxford Instruments announces Dr Kate Ross as winner of the 2018 Lee Osheroff Richardson Science Prize for North and South America February 20th, 2018

Computers aid discovery of new, inexpensive material to make LEDs with high color quality February 20th, 2018

Water

Rice U.'s one-step catalyst turns nitrates into water and air: NSF-funded NEWT Center aims for catalytic converter for nitrate-polluted water January 5th, 2018

A new way to mix oil and water: Condensation-based method developed at MIT could create stable nanoscale emulsions November 8th, 2017

Magnetized viruses attack harmful bacteria: Rice, China team uses phage-enhanced nanoparticles to kill bacteria that foul water treatment systems August 2nd, 2017

Bacteria-coated nanofiber electrodes clean pollutants in wastewater July 1st, 2017

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project