Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Combined molecular study techniques reveal more about DNA proteins

03.03.2011
Illinois researchers have combined two molecular imaging technologies to create an instrument with incredible sensitivity that provides new, detailed insight into dynamic molecular processes.

Physics professors Taekjip Ha and Yann Chemla and combined their expertise in single-molecule biophysics – fluorescence microscopy and optical traps, respectively – to study binding and unbinding of individual DNA segments to a larger strand. They and their joint postdoctoral researcher Matthew Comstock detail their technique in a paper published in the Feb. 20 online edition of Nature Methods.

Both professors, who are also affiliated with the U. of I. Institute for Genomic Biology, have particularly studied proteins and enzymes that regulate DNA, such as the enzyme helicase that unwinds DNA for duplication or transcription to RNA. Fluorescent microscopy techniques allow researchers to observe proteins as they conform and move, but often lack the spatial range to track the protein’s motion over distance.

Optical traps, meanwhile, enable researchers to study a protein’s translocation, but not its conformation. Chemla compares traditional optical traps to fishing. A single molecule of DNA is tethered between two attachment points, and the activity of a protein bound to it is only inferred from how it tugs on the tether, much like a fish at the end of a line. This can reveal a lot about a protein’s activity and motion, but the technique has glaring limitations as well. For example, it is difficult to know how many proteins or the types of proteins that are involved.

“Also, these proteins may do all sorts of things beyond tugging on our line that we may not be sensitive to,” Chemla said. “Fluorescence allows you to have an additional readout to actually see these things, and the key is that we can now measure them simultaneously. This work was a real synthesis of the expertise of two groups at the Center for the Physics of Living Cells at the U. of I.”

The combination allows Chemla, Ha and their group to measure both a protein’s motion – sensitive to translocation as small as one DNA base pair, a distance of only a few angstroms – and also conformational changes as it acts. This can reveal details about its mechanism that would not have been accessible before.

“It was a major technical challenge, but the final product is a one-of-a-kind instrument with unique capabilities,” Chemla said. “It's like taking a rudimentary, real-time ‘movie’ of what individual molecules are doing.”

The National Science Foundation, National Institutes of Health and the Howard Hughes Medical Institute supported this work.

Liz Ahlberg | EurekAlert!
Further information:
http://www.illinois.edu

More articles from Life Sciences:

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

nachricht The Nagoya Protocol Creates Disadvantages for Many Countries when Applied to Microorganisms
05.12.2016 | Leibniz-Institut DSMZ-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

High-precision magnetic field sensing

05.12.2016 | Power and Electrical Engineering

Construction of practical quantum computers radically simplified

05.12.2016 | Information Technology

NASA's AIM observes early noctilucent ice clouds over Antarctica

05.12.2016 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>