Navigation Links
Media highlights for February in Biophysical Journal
Date:3/10/2008

Bethesda, MD A new and notable article entitled Passage Times for Polymer Translocation Pulled through a Narrow Pore appears in Volume 94, Issue 5, of the Biophysical Journal, which is available online.

Passage Times for Polymer Translocation Pulled through a Narrow Pore

When polymeric molecules squeeze through a nanometer-sized pore in membranes, in a process known as translocation, they leave a distinct signature at the pore. Present-day techniques can exploit translocation to recognize individual polymeric molecules by analyzing these signatures. Interestingly, one encounters translocation more frequently as a serious bottleneck: the prospect of polymeric molecules passing through nanometer-sized pores in inter/intra-cellular membranes hinders efficient delivery of drug molecules to their activation sites, and of healthy gene fragments to their target sites in gene therapy.

The physics of translocation is complex since our intuition, based on the macroscopic world, fails: concepts, such as "translocation is slow because the pore resists the passage of the molecule through friction", cannot be trusted at the nanoscale. Instead, other concepts like fluctuations in translocation dynamics at a molecular level are much more important.

Recently, we have made a significant breakthrough in understanding the physics of translocation. Starting from the microscopic dynamics of the polymeric molecule, we showed that its translocation behavior is strongly dominated by "memory effects" in the molecule. Each translocative step forward for the molecule through the pore generates a restoring tension that makes a following backward step through the pore very likely: as if the molecule remembers that it took a step forward, and it wants to return to the previous step. Consequently, every part of the molecule passes back and forth through the pore many, many times. Two most striking consequences of these wild fluctuations are that under a constant pulling force, the speed of translocation is not uniform; and that a molecule twice as long does not take twice, but four times longer to translocate.

Having unraveled the memory effects of the molecule, we are in a pivotal position to devise new methods to suppress or enhance these memory effects --- and consequently, the back-and-forth fluctuation movements of the molecule through the pore --- by putting in control mechanisms to suit situation-specific requirements. For example, to facilitate faster delivery of drug molecules or healthy gene fragments one needs to suppress the memory effects, while to advance single-molecule characterization techniques using translocation, enhancement of the memory effects is required, so that a given part of the molecule revisits the pore more frequently.


'/>"/>

Contact: Ellen R. Weiss
eweiss@biophysics.org
301-634-7176
Biophysical Society
Source:Eurekalert

Related biology news :

1. 2008 Ocean Sciences Meeting -- media advisory 2
2. March GEOLOGY and GSA TODAY media highlights
3. Media highlights in the March 1 issue of Biophysical Journal
4. Priming scientists for successful media interviews
5. Media highlights in the January issues of Biophysical Journal
6. February Geology and GSA Today media highlights
7. Media advisory -- 2008 Ocean Sciences Meeting
8. Oliguridylation-mediated histone mRNA decay
9. Immediate action needed to save corals from climate change
10. Media highlights in the Dec. 15 issue of Biophysical Journal
11. Better protection for biomedial devices could result from Rutgers-Camden research
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/15/2016)... Research and Markets has announced ... 2016-2020,"  report to their offering.  , ... global gait biometrics market is expected to grow ... 2016-2020. Gait analysis generates multiple variables ... to compute factors that are not or cannot ...
(Date:3/29/2016)... LegacyXChange, Inc. (OTC: LEGX ... Protect are pleased to announce our successful effort to ... of writing instruments, ensuring athletes signatures against counterfeiting and ... athletes on LegacyXChange will be assured of ongoing proof ... Bill Bollander , CEO states, "By inserting ...
(Date:3/18/2016)... --> --> Competitive Landscape Analysis ... Physical infrastructure and Perimeter Surveillance & Detection Systems ... and the continuing migration crisis in the Middle ... led visiongain to publish this unique report, which is crucial ... & security companies in the border security market and the ...
Breaking Biology News(10 mins):
(Date:4/27/2016)... ... April 27, 2016 , ... The Pittcon Organizing Committee ... Chuck has been a volunteer member of Committee since 1987. Since then, he ... of directors and treasurer and was chairman for both the program and exposition committees. ...
(Date:4/27/2016)... and RESEARCH TRIANGLE PARK, N.C. ... UTHR ) announced today that Martine ... United Therapeutics will provide an overview and update on ... Annual Health Care Conference. The presentation ... 10:00 a.m. Eastern Time, and can be accessed via ...
(Date:4/27/2016)... ... April 27, 2016 , ... PathSensors, ... Scientific Advisory Board. Dr. Lamka will assist PathSensors in expanding the use of ... PathSensors deploys the CANARY® test platform for the detection of harmful pathogens, including ...
(Date:4/27/2016)... ... April 27, 2016 , ... Global Stem Cells Group and ... Symposium as other research and development initiatives for potential stem cell protocol management for ... Stem Cells Group executives began meeting to establish a working agenda and foster initiatives ...
Breaking Biology Technology: