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:3/23/2017)... Research and Markets has announced the addition of the "Global ... 2025" report to their offering. ... The Global Vehicle Anti-Theft System Market is ... next decade to reach approximately $14.21 billion by 2025. ... all the given segments on global as well as regional levels ...
(Date:3/22/2017)... 21, 2017 Optimove , provider ... retailers such as 1-800-Flowers and AdoreMe, today announced ... and Replenishment. Using Optimove,s machine learning algorithms, these ... and replenishment recommendations to their customers based not ... of customer intent drawn from a complex web ...
(Date:3/20/2017)... At this year,s CeBIT Chancellor Dr. Angela ... The Chancellor came to the DERMALOG stand together with the Japanese Prime ... partner country. At the largest German biometrics company the two government leaders ... iris recognition as well as DERMALOG´s multi-biometrics system.   ... ...
Breaking Biology News(10 mins):
(Date:4/24/2017)... ... April 24, 2017 , ... It ... a cellular milieu; however, the broad application of this cellular target engagement concept ... sensitive quantitative readouts. Cell-based thermal stabilization assays are valuable methods for particular applications, ...
(Date:4/21/2017)... ... 2017 , ... The University of Connecticut, in partnership with ... startups through the UConn Innovation Fund. The $1.5 million UConn Innovation Fund was ... , The UConn Innovation Fund provides investments of up to $100,000 to companies ...
(Date:4/21/2017)... ... April 21, 2017 , ... Frederick Innovative Technology ... of emerging technology-based businesses, recently earned a $77,518 grant from the Rural Maryland ... in 2004, FITCI is Frederick’s first incubator. A non-profit corporation, FITCI is a ...
(Date:4/20/2017)... (PRWEB) , ... April 20, 2017 , ... USDM ... for the life sciences and healthcare industries, is pleased to announce Holger Braemer ... established USDM subsidiary “USDM Europe GmbH” based in Germany. , Braemer is an ...
Breaking Biology Technology: