Featured Research

from universities, journals, and other organizations

Physicists delve into fundamental laws of biological materials

Date:
December 18, 2013
Source:
University of Chicago
Summary:
Physicists are uncovering the fundamental physical laws that govern the behavior of cellular materials.

Patrick McCall, graduate student in physics, prepares a sample for examination in the Gardel laboratory at UChicago. Gardel’s research group studies building blocks of the cytoskeleton, the materials inside a cell that provide its shape and allow it to move.
Credit: Robert Kozloff/University of Chicago

Physicists at the University of Chicago and the University of Massachusetts, Amherst, are uncovering the fundamental physical laws that govern the behavior of cellular materials.

"We don't have any tools or formalism to think about these types of materials, and that's what we've been trying to go after," said Margaret Gardel, professor in physics at UChicago. Gardel and Jennifer Ross of the University of Massachusetts, Amherst, are supported in this work by a four-year, $800,000 INSPIRE grant from the National Science Foundation.

Gardel studies the building blocks of the cytoskeleton -- the materials inside a cell that provide its shape and allow it to move -- by extracting proteins from the cell and studying how they interact in vitro. "These materials are what makes living cells living materials and not dead materials," said Gardel.

Biological materials behave differently than non-living materials because, unlike conventional materials, they are not in a state of equilibrium -- they constantly consume energy and do work with that energy. Studying the unique physics of such materials is interesting in its own right and could allow physicists to produce novel materials for applications outside the lab. "We are trying to take advantage of what is intrinsically new that these materials can do, that cannot be done by equilibrium material," said physics graduate student Patrick McCall, a member of Gardel's lab.

The NSF created the INSPIRE grants to fund interdisciplinary research that is innovative, and perhaps risky, but which could lead to big leaps in understanding. Gardel and Ross's research fits the bill because the scientists are working in uncharted territory -- without theories to guide their way -- as these materials are still poorly understood. "These systems are a part of nature that physics is not great at describing," Ross said.

Through their work, Gardel and Ross plan to catalog the phases of biological materials. Just as traditional materials can be in a solid, liquid, or gas phase, biological materials may have multiple phases where the materials behave in drastically different ways. Rather than temperature and pressure causing phase changes, the important variables to study might be the concentration or types of proteins in the mix.

One example of a phase transition in cellular material occurs with contractility, a quality that Gardel has studied extensively in her lab. Give biological materials the right conditions and they can contract, but change those conditions and suddenly contraction is no longer possible. Cells must contract to move, adhere to surfaces, and generate forces. Although contraction in skeletal and cardiac muscle cells has been well-understood for 60 years, finding a model of contraction for other types of cells has proven tricky. "That was sort of what I got stuck on when I started my lab," said Gardel.

Contraction in skeletal and cardiac muscle cells is generated by filaments made up of the protein actin in combination with the motor protein myosin. The myosin molecules walk along the filaments of actin, pulling the actin closer together and generating contraction along the filament. This model requires a precisely aligned network of actin and myosin, so that each tug causes the filament to get shorter, not longer. But this model does not explain contraction in other types of cells, which have disordered networks of actin. Research in Gardel's lab showed that the actin behaves like a rope, buckling out of the way when compressed, but resisting tension when pulled. This allows the whole network to compress, despite its disorder.

Gardel's research on contraction earned her a $450,000 Early Excellence Award from the American Asthma Foundation last year, which will allow her to study whether contraction in airway muscle cells can also be described by her model.

While Gardel's research has focused on actin, which is only one component of the cytoskeletal structure. Ross studies microtubules, which she describes as the "bones" of the cell, whereas actin is the muscle. "Much like the bones and muscles of your body work together to allow you to move, we believe the microtubules and actin cytoskeletons work in concert to enable cell shape changes and motility," said Ross.

Gardel's research brings the strategies of condensed matter physics (the physics of liquids and solids) to biological materials, with the goal of understanding how cells behave from the bottom up. The INSPIRE grant will allow Ross and Gardel to rigorously test cellular models and explore the underlying physics. "There are lots of theories out there about how these cytoskeletal structures are regulated, but very little quantitative physical data," Gardel said.


Story Source:

The above story is based on materials provided by University of Chicago. The original article was written by Emily Conover. Note: Materials may be edited for content and length.


Cite This Page:

University of Chicago. "Physicists delve into fundamental laws of biological materials." ScienceDaily. ScienceDaily, 18 December 2013. <www.sciencedaily.com/releases/2013/12/131218143647.htm>.
University of Chicago. (2013, December 18). Physicists delve into fundamental laws of biological materials. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2013/12/131218143647.htm
University of Chicago. "Physicists delve into fundamental laws of biological materials." ScienceDaily. www.sciencedaily.com/releases/2013/12/131218143647.htm (accessed April 17, 2014).

Share This



More Matter & Energy News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
German Researchers Crack Samsung's Fingerprint Scanner

German Researchers Crack Samsung's Fingerprint Scanner

Newsy (Apr. 16, 2014) German researchers have used a fake fingerprint made from glue to bypass the fingerprint security system on Samsung's new Galaxy S5 smartphone. Video provided by Newsy
Powered by NewsLook.com
Porsche CEO Says Supercar Is Not Dead: Cue the Spyder 918

Porsche CEO Says Supercar Is Not Dead: Cue the Spyder 918

TheStreet (Apr. 16, 2014) The Porsche Spyder 918 proves that, in an automotive world obsessed with fuel efficiency, the supercar is not dead. Porsche North America CEO Detlev von Platen attributes the brand's consistent sales growth -- 21% in 2013 -- with an investment in new technology and expanded performance dynamics. The hybrid Spyder 918 has 887 horsepower and 944 lb-ft of torque, but it can run 18 miles on just an electric charge. The $845,000 vehicle is not a consumer-targeted vehicle but a brand statement. Video provided by TheStreet
Powered by NewsLook.com
Industry's Optimism Shines At New York Auto Show

Industry's Optimism Shines At New York Auto Show

Newsy (Apr. 16, 2014) After seeing auto sales grow last month, there's plenty for the industry to celebrate as it rolls out its newest designs. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins