Contact Information:

Media Contact

Patrick Regan

Twitter: TU_Muenchen

Kredyty mieszkaniowe Kredyty mieszkaniowe

Sprawdź aktualny ranking najlepszych kredytów mieszkaniowych w Polsce - atrakcyjne kredytowanie nieruchomości. - Press Release Distribution
RSS - Press News Release
Add Press Release

All together now: Group behavior in biomolecular systems

Probing pattern formation and dynamics of nanoscale 'swarms'

All together now: Group behavior in biomolecular systems
( "Flocking" or "swarming" behavior is omnipresent in the living world, observed in birds, fish, and even bacteria. Strikingly similar collective action can also be seen in biomolecules within and between cells. Such self-organization processes are the basis of life - without them no living cell would exist - yet they are not well understood. New insights into how this action is coordinated at the biomolecular level are emerging from studies of a model system based on actin filaments. Experimental evidence proves the inadequacy of widely accepted explanations, according to collaborators at the Technical University of Munich (TUM), Ludwig-Maximilians-Universität München (LMU), and the Max Planck Institute for the Physics of Complex Systems (MPI-PKS).

Living matter, which consists largely of diverse polymeric structures assembled from various types of subunits, often exhibits striking behaviors, such as a capacity for self-organization and active motion. Physicists are interested in teasing out the elementary mechanisms that underlie the "self-organized" formation of such ordered structures and collective motions. Prof. Andreas Bausch and Dr. Ryo Suzuki of TUM, Prof. Erwin Frey of LMU, and Dr. Christoph Weber of MPI-PKS report progress toward this goal. Nanoscale filaments, made up of subunits of the protein actin, form the basis of the experimental model system they are investigating. Two papers, in the journals Nature Physics and the Proceedings of the National Academy of Sciences (PNAS), present their latest results.

Experiments disprove popular theory

In their experiments the researchers first immobilize motor proteins by fixing them to a glass slide. When actin filaments are added, together with a source of biochemical energy, they interact with the motors and exhibit active gliding motions. Moreover, individual filaments were found to locally adopt strongly curved configurations. The team analyzed their statistics to understand what happens when filaments collide and under what conditions interacting filaments align themselves in collective, streaming motions.

In living organisms, actin microfilaments are involved in the active migration of nucleated cells and in intracellular transport processes. According to the most popular theory, the fact that thin actin filaments bend as they are propelled by motor proteins is attributable to random thermal fluctuations, i.e., Brownian motion. But this assumption is false, says Christoph Weber, first author of the PNAS paper. Brownian motion has only a very weak impact on the form of the filaments. The researchers found that the molecular motors are not only responsible for propelling the fibers, but also for causing them to form strong bends.

"The filaments exhibit a range of local curvatures, the statistical distribution of which is incompatible with thermally driven motion," explains Ryo Suzuki, first author of the paper in Nature Physics.

Two by two won't do

In addition, the assumption that the interactions in the system are always binary in nature is not sufficient to explain the fact that, at high densities, filaments can align with each other and begin to display directed, collective motions. In fact, simultaneous encounters involving multiple agents appear to be required to account for the emergence of such collective motion. In this case, the filaments, each of which is composed of multiple subunits, apparently remain in stable alignment with each other and interact not only pairwise, but also with many other partners.

The scientists observed that, depending on the density and the mean length of the filaments, a phase transition occurs in which a state of non-directed movements is abruptly transformed into one characterized by collective motions ("swarm formation"). This transition resembles the condensation of a gas into the liquid state, except that in this case, it is not the pattern of microscopic molecular motions that changes but the orientation of the molecules in the system.

From a theoretical point of view, this strengthens the argument that the currently favored model for the motions of actively driven particles, which is based on the kinetic theory of gases, cannot adequately account for the behavior of such systems. Instead, it appears as if the filaments themselves act in a coordinated fashion, like molecules in a fluid state. "To understand how collective motion arises in these systems, we need to develop new theoretical concepts which go beyond the assumptions of the kinetic theory of gases," says LMU Prof. Erwin Frey.

Exactly what happens at the microscopic level when filaments come into alignment, i.e., how their subunits interact with neighbors or exchange places, is not yet clear. "A better understanding of the physics of active systems," says TUM Prof. Andreas Bausch, "opens the way to determining the basic mechanisms leading to structures and patterns enabling life, and could permit scientists to construct entirely novel nanosystems based on collective behaviors."


This research was supported by the European Research Council in the framework of the Advanced Grant 289712-SelfOrg, the German Research Foundation (DFG) within the Collaborative Research Center (SFB) No. 863, and by the German Excellence Initiative through the Excellence Cluster Nanosystems Initiative Munich (NIM).

Publications: Ryo Suzuki, Christoph A. Weber, Erwin Frey and Andreas R. Bausch: Polar pattern formation in driven filament systems requires non-binary particle collisions. Nature Physics 2015, 10.1038/nphys3423.

Christoph A. Weber, Ryo Suzuki, Volker Schaller, Igor S. Aranson, Andreas R. Bausch, and Erwin Frey: Random bursts determine dynamics of active filaments. Proceedings of the National Academy of Sciences (PNAS) 2015, 10.1073/pnas.1421322112.

Contact: Prof. Andreas Bausch
Technical University of Munich
Chair of Biophysics
Tel: +49 (0) 89 289 12480

Technische Universität München (TUM) is one of Europe's leading research universities, with around 500 professors, 10,000 academic and non-academic staff, and more than 37,000 students. Its focus areas are the engineering sciences, natural sciences, life sciences and medicine, reinforced by schools of management and education. TUM acts as an entrepreneurial university that promotes talents and creates value for society. In that it profits from having strong partners in science and industry. It is represented worldwide with a campus in Singapore as well as offices in Beijing, Brussels, Cairo, Mumbai, and São Paulo. Nobel Prize winners and inventors such as Rudolf Diesel and Carl von Linde have done research at TUM. In 2006 and 2012 it won recognition as a German "Excellence University." In international rankings, TUM regularly places among the best universities in Germany.

[Attachments] See images for this press release:
All together now: Group behavior in biomolecular systems All together now: Group behavior in biomolecular systems 2


Inspired by venus flytrap, researchers develop folding 'snap' geometry

AMHERST, Mass. - Inspired by natural "snapping" systems like Venus flytrap leaves and hummingbird beaks, a team led by physicist Christian Santangelo at the University of Massachusetts Amherst has developed a way to use curved creases to give thin curved shells a fast, programmable snapping motion. The new technique avoids the need for complicated materials and fabrication methods when creating structures with fast dynamics. The advance should help materials scientists and engineers who wish to design structures that can rapidly switch shape and properties, says Santangelo. ...

Passion for your job? If not, it's attainable

ANN ARBOR--People who have not found their perfect fit in a career can take heart: There is more than one way to attain passion for work. Contrary to popular wisdom, a love-at first-sight experience is not necessary when evaluating a potential job, according to a new University of Michigan study. "The good news is that we can choose to change our beliefs or strategies to cultivate passion gradually or seek compatibility from the outset, and be just as effective in the long run at achieving this coveted experience," said Patricia Chen, a doctoral psychology student and ...

How DNA 'proofreader' proteins pick and edit their reading material

Researchers from North Carolina State University and the University of North Carolina at Chapel Hill have discovered how two important proofreader proteins know where to look for errors during DNA replication and how they work together to signal the body's repair mechanism. When a cell prepares to divide, the DNA splits first, the double helix "unzipping" into two separate backbones. New nucleotides - adenine, cytosine, guanine or thymine - are filled into the gaps on the other side of the backbone, pairing with their counterparts (adenine with thymine and cytosine with ...

Anti-aging tricks from dietary supplement seen in mice

In human cells, shortened telomeres, the protective caps at the ends of chromosomes, are both a sign of aging and contribute to it. Scientists at Emory University School of Medicine have found that the dietary supplement alpha lipoic acid (ALA) can stimulate telomerase, the enzyme that lengthens telomeres, with positive effects in a mouse model of atherosclerosis. The discovery highlights a potential avenue for the treatment for chronic diseases. The results were published Thursday, August 20 in Cell Reports. "Alpha-lipoic acid has an essential role in mitochondria, ...

Impact of sleep disturbance on recovery in veterans with PTSD and TBI

(Boston)--Poor sleep may impact treatment and recovery in veterans with Post-Traumatic Stress Disorder (PTSD) and Traumatic Brain Injury (TBI). A review of extensive research on sleep in TBI and PTSD has found that sleep-focused interventions can improve treatment outcomes in veterans. Led by researchers at Boston University School of Medicine (BUSM) and VA Boston Healthcare System, the review article currently appears online in the journal of Clinical Psychology Review. Sleep difficulty is a primary symptom of both PTSD and TBI and has been found to affect the severity ...

Some single people are happy on their own, research finds

People who fear relationship conflicts are just as happy when they are single or in a relationship, according to new research published by the Society for Personality and Social Psychology. "It's a well-documented finding that single people tend to be less happy compared to those in a relationship, but that may not be true for everyone. Single people also can have satisfying lives," said lead researcher Yuthika Girme, a psychology doctoral candidate at the University of Auckland in New Zealand. In a survey of more than 4,000 New Zealand residents, a nationally ...

Water pollution in alluvial rivers is studied by an innovative and efficient approach

Water pollution in alluvial rivers is studied by an innovative and efficient approach
Water pollution has been a historical and stubborn problem in the water resource management. Several water pollution accidents continually occurred all over the world, threatening the safety of industry, agriculture and drinking water for resident's life (see Figure 1). An innovative and efficient approach was identified to study the complicated mechanism of water pollution in alluvial rivers. The article titled "Numerical Simulation of Pollution Process Due to Resuspension of Bed Materials Adsorbing Pollutants in Alluvial Rivers" was recently published in Science China ...

Researchers developing next generation of high power lasers

Researchers at the University of Strathclyde are developing groundbreaking plasma based light amplifiers that could replace traditional high power laser amplifiers. The research group at the Glasgow-based University are leading efforts to take advantage of plasma, the ubiquitous medium that makes up most of the universe, to make the significant scientific breakthrough. The next generation of high power lasers should be able to crack the vacuum to produce real particles from the sea of virtual particles. Example of these types of lasers can be found at the Extreme Light ...

Scientists warn of the risk from air pollution over the megacities of West Africa

New research by European and African scientists, including a team from the University of York, warns of the risks posed by the increasing air pollution over the cities of West Africa - amid fears it could have an impact on human health, meteorology and regional climate. The atmosphere above West Africa is still one of the least studied and understood on the planet, despite its central role for the health and economic wellbeing of a large and increasing population. Rapidly expanding cities such as Lagos in Nigeria, Accra in Ghana and Abidjan in Ivory Coast are producing ...

Something to chew on -- millions of lives blighted by smokeless tobacco

More than a quarter of a million people die each year from using smokeless tobacco, researchers at the University of York have concluded. Millions more have their lives shortened by ill health due to the effects of chewing tobacco-based products, the study reveals. Researchers say it is the first time the global impact of smokeless tobacco consumption on adults has been assessed. The team, which included collaboration from the University of Edinburgh and Imperial College, London, says governments and public health bodies need to consider incorporating the regulation ...


How your brain decides blame and punishment -- and how it can be changed

Uniquely human brain region enables punishment decisions

Pinpointing punishment

Chapman University publishes research on attractiveness and mating

E-cigarettes: Special issue from Nicotine & Tobacco Research

Placental problems in early pregnancy associated with 5-fold increased risk of OB & fetal disorders

UT study: Invasive brood parasites a threat to native bird species

Criminals acquire guns through social connections

Restoring ocean health

Report: Cancer remains leading cause of death in US Hispanics

Twin study suggests genetic factors contribute to insomnia in adults

To be fragrant or not: Why do some male hairstreak butterflies lack scent organs?

International team discovers natural defense against HIV

Bolivian biodiversity observatory takes its first steps

Choice of college major influences lifetime earnings more than simply getting a degree

Dominant strain of drug-resistant MRSA decreases in hospitals, but persists in community

Synthetic biology needs robust safety mechanisms before real world application

US defense agencies increase investment in federal synthetic biology research

Robots help to map England's only deep-water Marine Conservation Zone

Mayo researchers identify protein -- may predict who will respond to PD-1 immunotherapy for melanoma

How much water do US fracking operations really use?

New approach to mammograms could improve reliability

The influence of citizen science grows despite some resistance

Unlocking secrets of how fossils form

What happens on the molecular level when smog gets into the lungs?

Using ultrasound to clean medical instruments

Platinum and iron oxide working together get the job done

Tiny silica particles could be used to repair damaged teeth, research shows

A quantum lab for everyone

No way? Charity's logo may influence perception of food in package

[] All together now: Group behavior in biomolecular systems
Probing pattern formation and dynamics of nanoscale 'swarms' is a service of DragonFly Company. All Rights Reserved.
Issuers of news releases are solely responsible for the accuracy of their content.