Featured Research

from universities, journals, and other organizations

Biophysics: Order in chaos

Date:
May 2, 2012
Source:
The Agency for Science, Technology and Research (A*STAR)
Summary:
Scientists have built a model to illustrate the process of skeletal muscle contraction. A combination of random protein movements and the elasticity inside muscles helps to maintain a steady force during skeletal muscle contraction.

Bin Chen of the A*STAR Institute of High Performance Computing and Huajian Gao at Brown University, US, have built a model to illustrate the process of skeletal muscle contraction. A combination of random protein movements and the elasticity inside muscles helps to maintain a steady force during skeletal muscle contraction.

Related Articles


The process of skeletal muscle contraction is based around protein filaments sliding inside sarcomeres -- the structural units of muscle fiber. Inside each sarcomere is a set of filament motors, which appear in different densities in different areas. Scientists previously thought that the motor force would change according to the filament load in the muscle, but recent studies have shown that the motor force actually maintains a constant level during the muscle contraction. Despite such breakthroughs, however, it remains unclear exactly how this constant force is maintained in an otherwise chaotic system.

Bin Chen of the A*STAR Institute of High Performance Computing and Huajian Gao at Brown University, US, have now built a model to illustrate the process of skeletal muscle contraction and show how a constant force can be sustained by the protein motors.

The two key proteins in muscle contraction are actin and myosin. Myosin drives the system, forming a thick filament made up of numerous motors which 'grab' onto, bind to and slide past the thinner actin filaments during contraction. This 'grabbing' and sliding motion has been shown to be fairly chaotic in nature, with attachment and release happening at random. When the weight of an object exerts a load on the filaments -- for example, when you try to lift something up -- the muscles must contract, requiring the protein motors to generate a force opposite to the load.

Chen and Gao have created a new skeletal muscle fiber model to demonstrate how contraction forces work. "Our model is designed for the sarcomere," Chen explains. "We consider the thin filament as an elastic rod under a filament force, which is driven by multiple stochastic myosin motors that convert the chemical energy of adenosine-5'-triphosphate (ATP) hydrolysis into stored elastic energy and then function like swinging arms."

The results show that the unique way in which the myosin motors randomly attach and release from actin, coupled with the elastic properties of the motors, generate a consistent force across the whole sarcomere. When there is a higher filament load, more myosin motors are attached to the actin, but the overall motor force remains constant.

"This regulation mechanism may exist in various biological processes and dramatically induces order within a chaotic system," explains Chen. "Our modeling framework can also be further adapted to study the behaviors of other actomyosin complex structures, which is part of our plan for future work in this area."


Story Source:

The above story is based on materials provided by The Agency for Science, Technology and Research (A*STAR). Note: Materials may be edited for content and length.


Journal Reference:

  1. Bin Chen, Huajian Gao. Motor Force Homeostasis in Skeletal Muscle Contraction. Biophysical Journal, 2011; 101 (2): 396 DOI: 10.1016/j.bpj.2011.05.061

Cite This Page:

The Agency for Science, Technology and Research (A*STAR). "Biophysics: Order in chaos." ScienceDaily. ScienceDaily, 2 May 2012. <www.sciencedaily.com/releases/2012/05/120502091613.htm>.
The Agency for Science, Technology and Research (A*STAR). (2012, May 2). Biophysics: Order in chaos. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2012/05/120502091613.htm
The Agency for Science, Technology and Research (A*STAR). "Biophysics: Order in chaos." ScienceDaily. www.sciencedaily.com/releases/2012/05/120502091613.htm (accessed October 25, 2014).

Share This



More Health & Medicine News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Texas Nurse Nina Pham Cured of Ebola

Texas Nurse Nina Pham Cured of Ebola

AFP (Oct. 25, 2014) — An American nurse who contracted Ebola while caring for a Liberian patient in Texas has been declared free of the virus and will leave the hospital. Duration: 01:01 Video provided by AFP
Powered by NewsLook.com
Toxin-Packed Stem Cells Used To Kill Cancer

Toxin-Packed Stem Cells Used To Kill Cancer

Newsy (Oct. 25, 2014) — A Harvard University Research Team created genetically engineered stem cells that are able to kill cancer cells, while leaving other cells unharmed. Video provided by Newsy
Powered by NewsLook.com
IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) — IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) — A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
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:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

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