Nano springs eternal; Protozoan 'engine' posts nano records

December 11, 2005

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 spasmoneme's 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 centrin's 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."
-end-


American Society for Cell Biology

Related Microscope Articles from Brightsurf:

Microscope lens inspired by lighthouse
Custom-fabricated lenses make it easy to attach high-tech microscopes directly to cell incubators.

Print your own laboratory-grade microscope for US$18
For the first time, labs around the world can 3D print their own precision microscopes, thanks to an open-source design created at Bath.

Novel high-speed microscope captures brain neuroactivities
A research team led by Dr. Kevin Tsia from the University of Hong Kong (HKU); and Professor Ji Na, from the University of California, Berkeley (UC Berkeley) has successfully recorded the millisecond electrical signals in the neurons of an alert mouse with their super high-speed microscope - two-photon fluorescence microscope.

Graphene forms under microscope's eye
Scientists record the formation of foamy laser-induced graphene made with a small laser mounted to a scanning electron microscope.

Hybrid microscope could bring digital biopsy to the clinic
By adding infrared capability to the ubiquitous, standard optical microscope, researchers at the University of Illinois at Urbana-Champaign hope to bring cancer diagnosis into the digital era.

An ultrafast microscope for the quantum world
Processes taking place inside tiny electronic components or in molecules can now be filmed at a resolution of a few hundred attoseconds and down to the individual atom.

SLAP microscope smashes speed records
A new 2-photon microscope captures videos of the brain faster than ever, revealing voltage changes and neurotransmitter release.

New 3D microscope visualises fast biological processes better than ever
Researchers from the European Molecular Biology Laboratory (EMBL) in Heidelberg have combined their expertise to develop a new type of microscope.

Use a microscope as a shovel? UConn researchers dig it
Using a familiar tool in a way it was never intended to be used opens up a whole new method to explore materials, report UConn researchers.

New method gives microscope a boost in resolution
Scientists at the University of W├╝rzburg have been able to boost current super-resolution microscopy by a novel tweak.

Read More: Microscope News and Microscope Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.