Navigation Links
Biological molecules select their spin
Date:3/31/2011

Do the principles of quantum mechanics apply to biological systems? Until now, says Prof. Ron Naaman of the Institute's Chemical Physics Department (Faculty of Chemistry), both biologists and physicists have considered quantum systems and biological molecules to be like apples and oranges. But research he conducted together with scientists in Germany, which appeared recently in Science, definitively shows that a biological molecule DNA can discern between quantum states known as spin.

Quantum phenomena, it is generally agreed, take place in extremely tiny systems single atoms, for instance, or very small molecules. To investigate them, scientists must usually cool their material down to temperatures approaching absolute zero. Once such a system exceeds a certain size or temperature, its quantum properties collapse, and 'every day' classical physics takes over. Naaman: 'Biological molecules are quite large, and they work at temperatures that are much warmer than the temperatures at which most quantum physics experiments are conducted. One would expect that the quantum phenomenon of spin, which exists in two opposing states, would be scrambled in these molecules and thus irrelevant to their function.'

But biological molecules have another property: they are chiral. In other words, they exist in either 'left-' or 'right-handed' forms that can't be superimposed on one another. Double-stranded DNA molecules are doubly chiral both in the arrangement of the individual strands and in the direction of the helices' twist. Naaman knew from previous studies that some chiral molecules can interact in different ways with the two different spins. Together with Prof. Zeev Vager of the Particle Physics and Astrophysics Department, research student Tal Markus, and Prof. Helmut Zacharias and his research team at the University of M?nster, Germany, he set out to discover whether DNA might show some spin-selective properties.

The researchers fabricated self-assembling, single layers of DNA attached to a gold substrate. They then exposed the DNA to mixed groups of electrons with both directions of spin. Indeed, the team's results surpassed expectations: The biological molecules reacted strongly with the electrons carrying one of those spins, and hardly at all with the others. The longer the molecule, the more efficient it was at choosing electrons with the desired spin, while single strands and damaged bits of DNA did not exhibit this property. These findings imply that the ability to pick and choose electrons with a particular spin stems from the chiral nature of the DNA molecule, which somehow 'sets the preference' for the spin of electrons moving through it.

In fact, says Naaman, DNA turns out to be a superb 'spin filter,' and the team's findings could have relevance for both biomedical research and the field of spintronics. If further studies, for instance, bear out the finding that DNA only sustains damage from spins pointing in one direction, then exposure might be reduced and medical devices designed accordingly. On the other hand, DNA and other biological molecules could become a central feature of new types of spintronic devices, which will work on particle spin rather than electric charge, as they do today.


'/>"/>

Contact: Yivsam Azgad
news@weizmann.ac.il
972-893-43856
Weizmann Institute of Science
Source:Eurekalert

Related biology technology :

1. Tips on how to build a better home for biological parts
2. Neurobiological Technologies Announces Dates for 2008 Fiscal Year End Financial Results Conference Call and Presentation at MCF Investor Summit
3. Neurobiological Technologies, Inc. (Nasdaq: NTII) Q4/08 Review Issued by Scimitar Equity, LLC
4. Tips on how to build a better home for biological parts
5. Neurobiological Technologies Announces Update Call on Viprinex (TM) Phase 3 Trial Program
6. Neurobiological Technologies to Present at the BIO Investor Forum in San Francisco on October 30, 2008
7. Neurobiological Technologies Reports Receipt of $2 Million Royalty Payment for Quarterly Sales of Memantine
8. The MathWorks Sponsors iGEM Competition for Synthetic Biology at MIT : MATLAB and SimBiology Help Accelerate Design of Synthetic Biological Systems
9. Neurobiological Technologies Sets Date for First Quarter Financial Results
10. Neurobiological Technologies to Present at the Rodman & Renshaw 10th Annual Healthcare Conference in New York on November 10
11. Neurobiological Technologies, Inc. Reports First Quarter Fiscal Year 2009 Financial Results
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/23/2016)... ... June 23, 2016 , ... ... its second eBook, “Clinical Trials Patient Recruitment and Retention Tips.” Partnering with experienced ... this eBook by providing practical tips, tools, and strategies for clinical researchers. , ...
(Date:6/23/2016)... 23, 2016 Houston Methodist Willowbrook Hospital ... Sports Association to serve as their official health ... Methodist Willowbrook will provide sponsorship support, athletic training ... association coaches, volunteers, athletes and families. ... Sports Association and to bring Houston Methodist quality ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... the launch of the Supplyframe Design Lab . Located in Pasadena, Calif., ... the future of how hardware projects are designed, built and brought to market. ...
(Date:6/23/2016)... -- Andrew D Zelenetz , ... Published recently in Oncology & ... Andrew D Zelenetz , discusses the fact ... placing an increasing burden on healthcare systems worldwide, ... the patents on many biologics expiring, interest in ...
Breaking Biology Technology:
(Date:6/16/2016)... 2016 The global ... reach USD 1.83 billion by 2024, according to ... Technological proliferation and increasing demand in commercial buildings, ... drive the market growth.      (Logo: ... development of advanced multimodal techniques for biometric authentication ...
(Date:6/7/2016)... , June 7, 2016  Syngrafii Inc. and ... business relationship that includes integrating Syngrafii,s patented LongPen™ ... project. This collaboration will result in greater convenience ... credit union, while maintaining existing document workflow and ... ...
(Date:6/2/2016)... Perimeter Surveillance & Detection Systems, ... Infrastructure, Support & Other Service  The latest ... comprehensive analysis of the global Border Security market ... of $17.98 billion in 2016. Now: In ... in software and hardware technologies for advanced video surveillance. ...
Breaking Biology News(10 mins):