Nano springs eternal; Protozoan engine posts nano records
Bioscience news from the cell biology meeting in San Francisco
Looking through his handmade microscope in 1702, it was Anton van Leeuwenhoek who first described the workings of a nano machine. He observed the rapid contraction of a stalk tethering the cell body of a tiny protozoan, Vorticella convallaria, to the surface of a leaf. Little did van Leeuwenhoek imagine that more than 300 years later, the biological spring that drives Vorticella would set records for speed and power in the nano world of cellular engines. It might also power future generations of nano devices and materials, according to biological engineer Danielle Cook France and colleagues at MIT, the Whitehead Institute, the Marine Biological Laboratory, and the University of Illinois, Chicago. France presented her findings Sunday at the 45th Annual Meeting of the American Society for Cell Biology in San Francisco.
The spring in the unicellular Vorticella is a contractile fiber bundle, called the spasmoneme, which runs the length of the stalk. At rest, the stalk is elongated like a stretched telephone cord. When it contracts, the spasmoneme winds back in a flash, forming a tight coil. To find out how fast and how hard Vorticella recoils, France and colleagues used modern microscopes and tools to measure the force and speed of the spring. This is one powerful engine, France reports. The spasmonemes contraction is measured in nano-newtons of force and centimeters/second of speed in a biological world where the ruler markings are usually in tiny pico-newtons and micrometers/second. Gram for gram, the power of the spasmoneme engine outperforms human muscles and car engines.
It also runs on a different fuel. Molecular motors that power muscle contraction, for example, use ATP molecules for energy. The spasmoneme runs on calcium, but its drive mechanism was poorly understood until France and colleagues got under the nano hood. Like van Leeuwenhoek, the researchers studied Vorticella under the microscope but they also had specialized biochemical methods to slow and inhibit the contraction, to freeze-frame it, and to discern details of the calcium fuel system.
Earlier research had identified a cellular protein, spasmin, as the possible calcium-responsive component of the stalk. "The Vorticella spasmins are now known to belong to the centrin family of calcium-binding proteins," says France. "Centrins are ubiquitous to eukaryotic cells and some family members are found in filamentous structures in organisms other than Vorticella, ranging from green algae to humans."
In sorting out centrins role in the Vorticella spring, France and colleagues found that an antibody to Vorticella centrin abolished contractility. Along with other evidence, this interference suggests that the spasmoneme uses a powerful centrin-based mechanism that is unlike any complex actin or microtubule-based cellular engine, says France. "This leads us closer to understanding two things: how cells use centrin-based engines to generate enormous forces and how we can possibly reconstruct centrin-based materials and devices for our own use at the micrometer and nanometer scales."
John Fleischman | EurekAlert!
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
A study carried out by an international team of researchers and published in the journal Physical Review X shows that ion-trap technologies available today are suitable for building large-scale quantum computers. The scientists introduce trapped-ion quantum error correction protocols that detect and correct processing errors.
In order to reach their full potential, today’s quantum computer prototypes have to meet specific criteria: First, they have to be made bigger, which means...
German and Spanish researchers plan, build and use modern spectrograph
Since 2016, German and Spanish researchers, among them scientists from the University of Göttingen, have been hunting for exoplanets with the “Carmenes”...
DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.
Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...
MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.
Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...
Detailed calculations show water cloaks are feasible with today's technology
Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...