Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers find the mechanism that forms cell-to-cell catch bonds

06.06.2014

Certain bonds connecting biological cells get stronger when they’re tugged.

Those bonds could help keep hearts together and pumping; breakdowns of those bonds could help cancer cells break away and spread.


This ribbon diagram shows a pulling force applied to two common adhesion proteins called cadherins (red and blue) bound together in an X-shape. The green spheres represent calcium ions while the cyan and orange stick figures correspond to amino acids brought together as the force is applied. The hydrogen bonds that form between the amino acids create catch bonds that get stronger when pulled. Larger image. Image courtesy of Sanjeevi Sivasankar

Those bonds are known as catch bonds and they’re formed by common adhesion proteins called cadherins. Sanjeevi Sivasankar, an Iowa State University assistant professor of physics and astronomy and an associate of the U.S. Department of Energy’s Ames Laboratory, has described catch bonds as “nanoscale seatbelts. They become stronger when pulled.”

But how does that happen? How can bonds get stronger under force? Sivasankar and his research team have found long-lived, force-induced hydrogen bonds are the answer. A paper describing their findings, “Resolving the molecular mechanism of cadherin catch bond formation,” has just been published online by Nature Communications. Sivasankar is the corresponding author.

Co-authors are Kristine Manibog, an Iowa State graduate student in physics and astronomy and a student associate of the Ames Laboratory; Hui Li, of the Suzhou Institute of Biomedical Engineering and Technology of the Chinese Academy of Sciences in Suzhou New District, China; and Sabyasachi Rakshit, of the Indian Institute of Science Education and Research in Mohali, India. Li and Rakshit are former postdoctoral researchers in Sivasankar’s laboratory.

The team’s research was supported by grants from the American Cancer Society and the American Heart Association. Sivasankar said strong cell-to-cell bonds are important to heart health and fighting cancer. He said the bonds connecting heart cells have to withstand constant mechanical forces. And, in some cancers, he said bonds no longer resist forces, allowing cancer cells to detach and spread.

To find the mechanism behind the strong ties created by catch bonds, Sivasankar’s research team began with molecular dynamics and steered molecular dynamics computer simulations based on data from previous experiments. They found that two rod-shaped cadherins bound together in an X-shape (called an X-dimer) form catch bonds when pulled and in the presence of calcium ions.

The calcium ions keep the cadherins rigid and ordered while the pulling brings parts of the proteins closer together. All of that allows a series of hydrogen bonds to form. These long-lived, force-induced hydrogen bonds lock the X-dimers into tighter contact. Sivasankar said the researchers followed up the simulations with single-molecule experiments using atomic force microscopy.

The experiments confirmed that cadherin X-dimers, when pulled and exposed to high calcium ion concentrations, formed catch bonds. Take away the force or the calcium ions, and catch bond formation was eliminated.

All of this, Sivasankar said, helps explain the biophysics of cell-to-cell adhesion. And that’s important to all of us. “Robust cadherin adhesion,” the researchers wrote in their paper, “is essential for maintaining the integrity of tissue such as the skin, blood vessels, cartilage and muscle that are exposed to continuous mechanical assault.”

Sanjeevi Sivasankar | Eurek Alert!
Further information:
http://www.news.iastate.edu/news/2014/06/05/catchbonds

More articles from Life Sciences:

nachricht Shark Tagged by NSU’s Guy Harvey Research Institute Is Apparently Enjoying Time in Warm, Tropical Waters
30.03.2015 | Nova Southeastern University

nachricht Misuse of Sustainability Concept May Lead to Even More Toxic Chemical Materials
30.03.2015 | Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energy-autonomous and wireless monitoring protects marine gearboxes

The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.

As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...

Im Focus: 3-D satellite, GPS earthquake maps isolate impacts in real time

Method produced by UI researcher could improve reaction time to deadly, expensive quakes

When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.

Im Focus: Atlantic Ocean overturning found to slow down already today

The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe. 

Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...

Im Focus: Robot inspects concrete garage floors and bridge roadways for damage

Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.

From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

10. CeBiTec Symposium zum Big Data-Problem

17.03.2015 | Event News

 
Latest News

BLS Cargo orders 15 multisystem locomotives

30.03.2015 | Press release

Shark Tagged by NSU’s Guy Harvey Research Institute Is Apparently Enjoying Time in Warm, Tropical Waters

30.03.2015 | Life Sciences

Antarctic Ice Shelves Rapidly Thinning

30.03.2015 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>