Navigation Links
Biological molecules select their spin

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
Weizmann Institute of Science

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:
(Date:10/13/2015)... ... October 13, 2015 , ... ... announced that it has received a Phase I Small Business Innovative Research (SBIR) ... Institute of General Medical Sciences (NIGMS), will fund the development of a technique ...
(Date:10/13/2015)... Oct. 13, 2015  According to Kalorama Information, ... reach $102 billion by the end of 2015. ... health industry, as it is estimated that approximately ... laboratory tests. In addition to diagnosing patients, clinical ... disease progression, monitor drug treatment and conditions, and ...
(Date:10/13/2015)... NC (PRWEB) , ... October 13, 2015 , ... ... intensity focused ultrasound (HIFU) technologies, announced today that it received de novo clearance ... in the U.S. for the ablation of prostate tissue. Sonablate® is the ...
(Date:10/12/2015)... , Oct. 12, 2015  Amgen (NASDAQ: AMGN ... from an exploratory sub-study of the previously reported romosozumab Phase ... an oral plenary session at the American Society for Bone ... Seattle . 2 --> ... sub-study data showed that, at month 12, the investigational bone-forming ...
Breaking Biology Technology:
(Date:9/30/2015)... PALM BEACH GARDENS, Fla. , Sept. 30, 2015 ... Circuit earlier this month issued another key ruling in ... Commission,s (ITC,s) determination that Korean fingerprint scanner company Suprema ... the Tariff Act of 1930, a trade provision that ... connection with import trade, by infringing two of Crossmatch,s ...
(Date:9/29/2015)... -- News facts: , ... , Minimized design shrinks PC footprint , ... embedded Fujitsu PalmSecure authentication enable enterprises to realize benefits ... that good things come in small packages, with the ... desktop and mobile portfolio. Featuring workplace design that favors ...
(Date:9/28/2015)... 2015 CLEAR, the leading biometric ... traveler service is coming to Austin-Bergstrom International ... a frictionless experience, serious speed and enhanced ... offers our travelers an expedited security screening ... Jim Smith , Executive Director, Austin-Bergstrom International ...
Breaking Biology News(10 mins):