Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Biophysicists manipulate 'zipper,' reveal protein folding dynamics

19.01.2010
Single-molecule, real-time measurements of a key biological process

Biophysicists at TUM, the Technische Universitaet Muenchen, have published the results of single-molecule experiments that bring a higher-resolution tool to the study of protein folding.

How proteins arrive at the three-dimensional shapes that determine their essential functions – or cause grave diseases when folding goes wrong – is considered one of the most important and least understood questions in the biological and medical sciences.

Folding itself follows a path determined by its energy landscape, a complex property described in unprecedented detail by the TUM researchers. In this week's issue of the Proceedings of the National Academy of Sciences (USA), they report taking hold of a single, zipper-like protein molecule and mapping changes in its energy landscape during folding and unfolding.

Previous studies, including atomic force microscopy experiments by the same Munich laboratory, have gone a long way toward characterizing energy thresholds or barriers that stand between a protein's unfolded and folded states. Detailed observations of the quick transition from one state to the other have remained elusive. The results published this week open the door to higher-resolution, direct measurements. Better characterization of the folding process is seen as a vital link in understanding the chain of events leading from DNA coding for a protein to that protein's biological function. Another motivation for research in this field is the search for new drugs and therapies, because malfunctions in protein folding are implicated in a number of serious diseases – including diabetes, cancer, cystic fibrosis, prion diseases, and Alzheimer's.

This is the latest in a long series of single-molecule biophysical experiments carried out by Professor Matthias Rief and colleagues in the TUM Department of Physics. Co-authors Christof Gebhardt and Thomas Bornschloegl are members of Rief's lab; Gebhardt also is a member of the Munich Center for Integrated Protein Science.

As a model system for studying real-time protein folding dynamics, the TUM scientists chose a so-called leucine zipper found in yeast. It offers, as proteins go, a relatively simple "coiled coil" structure and zipper-like folding action: Picture two amino acid strings side by side, joined at the bottom, open at the top, and made essentially to zip together.

The researchers extended this structure so that they could make independent measurements at the top, bottom, and middle parts of the zipper. They took hold of the free ends at the top of the zipper with handles made of double-stranded DNA. These DNA handles in turn were attached to tiny beads that could be directly manipulated by "optical tweezers" – a tool based on the ability of laser beams with a certain kind of profile to pin down nanoscale objects. One end of the protein molecule was held fixed, and the other was held under tension but with some freedom to move, so that folding dynamics could be measured directly, in real time, as the protein zipped and unzipped. This arrangement enabled measurements with high resolution in both space and time.

"What I consider the major improvement is that the new experiments allow the observation of thousands of transitions between the folded and the unfolded state," Rief said. "This enables us to detect not only the folded and unfolded states but also, directly, the excursions of the large energy barriers separating those states. This has previously been impossible, and it now allows direct insight into the precise energy profile of this barrier."

Publication: Full distance resolved folding energy landscape of one single protein molecule, by J. Christof M. Gebhart, Thomas Bornschloegl, and Matthias Rief, PNAS Early Edition for the week of Jan. 18, 2010.

Contact:

Prof. Matthias Rief
Chair for Experimental Physics
Technische Universität Muenchen (TUM)
James-Franck-Str. 1
85748 Garching, Germany
Tel: +49 89 289 12471
Fax: +49 89 289 12523
E-mail: mrief@ph.tum.de

Patrick Regan | EurekAlert!
Further information:
http://portal.mytum.de

More articles from Life Sciences:

nachricht At last, butterflies get a bigger, better evolutionary tree
16.02.2018 | Florida Museum of Natural History

nachricht New treatment strategies for chronic kidney disease from the animal kingdom
16.02.2018 | Veterinärmedizinische Universität Wien

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

Im Focus: Autonomous 3D scanner supports individual manufacturing processes

Let’s say the armrest is broken in your vintage car. As things stand, you would need a lot of luck and persistence to find the right spare part. But in the world of Industrie 4.0 and production with batch sizes of one, you can simply scan the armrest and print it out. This is made possible by the first ever 3D scanner capable of working autonomously and in real time. The autonomous scanning system will be on display at the Hannover Messe Preview on February 6 and at the Hannover Messe proper from April 23 to 27, 2018 (Hall 6, Booth A30).

Part of the charm of vintage cars is that they stopped making them long ago, so it is special when you do see one out on the roads. If something breaks or...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Fingerprints of quantum entanglement

16.02.2018 | Information Technology

'Living bandages': NUST MISIS scientists develop biocompatible anti-burn nanofibers

16.02.2018 | Health and Medicine

Hubble sees Neptune's mysterious shrinking storm

16.02.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>